Answer:
d. No, you should examine the situation to identify lurking variables that may be influencing both variables
Step-by-step explanation:
Hello!
Finding out that there is a regression between two variables is not enough to claim that there is a causation relationship between the two of them. First you have to test if other factors are affecting the response variable, if so, you have to control them or test how much effect they have. Once you controled all other lurking variables you need to design an experiment, where only the response and explanatory variables are left uncontroled, to learn if there is a regression and its strenght.
If after the experiment, you find that there is a significally strog relationship between the variables, then you can imply causation between the two of them.
I hope it helps!
Vehicles arrive at an intersection at a rate of 400 veh/h according to a Poisson distribution. What is the probability that more than five vehicles will arrive in a one-minute interval?
Answer:
0.6547 or 65.47%
Step-by-step explanation:
One minute equals 1/60 of an hour, the mean number of occurrences in that interval is:
[tex]\lambda =\frac{400}{60}=6.6667[/tex]
The poisson distribution is described by the following equation:
[tex]P(x) =\frac{\lambda^{x}*e^{-\lambda}}{x!}[/tex]
The probability that more than 5 vehicles will arrive is:
[tex]P(x>5)= 1-(P(0)+P(1)+P(2)+P(3)+P(4)+P(5))\\P(x>5) = 1-(\frac{6.667^{0}*e^{-6.667}}{1}+\frac{6.667^{1}*e^{-6.667}}{1}+\frac{6.667^{2}*e^{-6.667}}{2}+\frac{6.667^{3}*e^{-6.667}}{3*2}+\frac{6.667^{4}*e^{-6.667}}{4*3*2}+\frac{6.667^{5}*e^{-6.667}}{5*4*3*2})\\P(x>5)=1-(0.00127+0.00848+0.02827+ 0.06283+0.10473+0.13965)\\P(x>5)=0.6547[/tex]
The probability that more than five vehicles will arrive in a one-minute interval is 0.6547 or 65.47%.
The probability that more than five vehicles will arrive in a one-minute interval is approximately 0.6582.
Step 1
Given that vehicles arrive at an intersection at a rate of 400 vehicles per hour, and this follows a Poisson distribution, we want to find the probability that more than five vehicles will arrive in a one-minute interval.
First, convert the arrival rate to a one-minute interval. Since there are 60 minutes in an hour, the arrival rate per minute is:
[tex]\[ \lambda = \frac{400 \, \text{veh/h}}{60} = \frac{400}{60} \approx 6.67 \, \text{veh/min} \][/tex]
The Poisson distribution formula for the probability of observing k events in an interval is:
[tex]\[ P(X = k) = \frac{e^{-\lambda} \lambda^k}{k!} \][/tex]
We need the probability that more than five vehicles arrive in one minute:
[tex]\[ P(X > 5) = 1 - P(X \leq 5) \][/tex]
Step 2
First, calculate [tex]\( P(X \leq 5) \)[/tex] by summing the probabilities for k = 0 to k = 5 :
[tex]\[ P(X \leq 5) = \sum_{k=0}^{5} \frac{e^{-6.67} 6.67^k}{k!} \][/tex]
Let's calculate these probabilities:
- For k = 0 :
[tex]\[ P(X = 0) = \frac{e^{-6.67} 6.67^0}{0!} = e^{-6.67} \][/tex]
- For k = 1 :
[tex]\[ P(X = 1) = \frac{e^{-6.67} 6.67^1}{1!} = e^{-6.67} \times 6.67 \][/tex]
- For k = 2 :
[tex]\[ P(X = 2) = \frac{e^{-6.67} 6.67^2}{2!} = e^{-6.67} \times \frac{6.67^2}{2} \][/tex]
- For k = 3:
[tex]\[ P(X = 3) = \frac{e^{-6.67} 6.67^3}{3!} = e^{-6.67} \times \frac{6.67^3}{6} \][/tex]
- For k = 4 :
[tex]\[ P(X = 4) = \frac{e^{-6.67} 6.67^4}{4!} = e^{-6.67} \times \frac{6.67^4}{24} \][/tex]
- For k = 5 :
[tex]\[ P(X = 5) = \frac{e^{-6.67} 6.67^5}{5!} = e^{-6.67} \times \frac{6.67^5}{120} \][/tex]
Sum these probabilities to find [tex]\( P(X \leq 5) \)[/tex].
Step 3
Next, we calculate [tex]\( e^{-6.67} \)[/tex] and the terms:
[tex]\[e^{-6.67} \approx 0.00126\][/tex]
[tex]\[P(X = 0) \approx 0.00126\][/tex]
[tex]\[P(X = 1) \approx 0.00126 \times 6.67 = 0.0084\][/tex]
[tex]\[P(X = 2) \approx 0.00126 \times \frac{6.67^2}{2} = 0.0280\][/tex]
[tex]\[P(X = 3) \approx 0.00126 \times \frac{6.67^3}{6} = 0.0622\][/tex]
[tex]\[P(X = 4) \approx 0.00126 \times \frac{6.67^4}{24} = 0.1037\][/tex]
[tex]\[P(X = 5) \approx 0.00126 \times \frac{6.67^5}{120} = 0.1382\][/tex]
Sum these probabilities:
[tex]\[P(X \leq 5) \approx 0.00126 + 0.0084 + 0.0280 + 0.0622 + 0.1037 + 0.1382 = 0.34176\][/tex]
Finally, the probability that more than five vehicles will arrive in a one-minute interval is:
[tex]\[P(X > 5) = 1 - P(X \leq 5) = 1 - 0.34176 = 0.65824\][/tex]
The probability that more than five vehicles will arrive in a one-minute interval is approximately 0.6582.
Select the most likely answer for the coefficient of linear correlation for the following two variables: x = the number of hours spent studying for a test, and y = the number of points earned on the test
a. r = 1.20b. r = 0.70c. r = - 0.85d. r = 0.05
Answer:
Option b) r = 0.70
Step-by-step explanation:
We are given the following in he question:
Variables:
x = the number of hours spent studying for a test
y = the number of points earned on the test
Correlation is a technique that help us to find or define a relationship between two variables. A positive correlation means that an increase in one quantity leads to an increase in another quantityA negative correlation means with increase in one quantity the other quantity decreases.+1 tells about a a perfect positive linear relationship and −1 indicates a perfect negative linear relationship.Values between 0 and 0.3 tells about a weak positive linear relationship, values between 0.3 and 0.7 shows a moderate positive correlation and a correlation of 0.7 and 1.0 states a strong positive linear relationship.Values between 0 and -0.3 tells about a weak negative linear relationship, values between -0.3 and -0.7 shows a moderate negative correlation and a correlation value of of -0.7 and -1.0 states a strong negative linear relationship.As the number of hours increases, the number of points earned on the test increases. Thus, the two variables are positively correlated.
Thus, the coefficient correlation between two variables can be given by r = 0.70, that shows a moderate positive correlation.
Option b) r = 0.70
Fereydoun is conducting a study of the annual incomes of high school teachers in metropolitan areas of fewer than 100,000 population, and in metropolitan areas having greater than 500,000 population.
If computed z value is 16.1, can he conclude that the annual incomes of high school teachers in metropolitan areas having greater than 500,000 population are significantly greater than those paid in areas with fewer than 100,000 population, at 0.05 level of significance?
Answer:
Yes, the claim can be concluded.
Step-by-step explanation:
We are given the following in the question:
Alpha, α = 0.05
The null hypothesis and alternate hypothesis can be designed in the following manner:
[tex]H_{0}: \mu_{500,000} = \mu_{100,000}\\H_A: \mu_{500,000} > \mu_{100,000}[/tex]
This is a one tailed(right) test.
[tex]z_{stat} = 16.2[/tex]
Now, we calculate the p - value from standard table.
P-value = 0.00001
Since the p value is less than the significance level, we fail to accept the null hypothesis and reject it.
We accept the alternate hypothesis.
Thus, we conclude that there is enough evidence to support the claim that the annual incomes of high school teachers in metropolitan areas having greater than 500,000 population are significantly greater than those paid in areas with fewer than 100,000 population.
A police office will hold an 18-session lesson. For every session, there are 7 days and there is no break between every two sessions . If the session can only be hold on weekdays and if the first session start on Friday, what day is the last day?
Answer:
Wednesday
Step-by-step explanation:
A 18 sessions and we know that a session lasts 7 days. We also know that the sessions are grouped and that there is only a break after every 2 sessions. The sessions can only be held on weekdays which is 5 days. The first session starts on Friday. We need to determine the last day of the 18 sessions.
WE can assume that a break is a one day.
The first two sessions will be a total of 14 days and then a break. Friday adding 14 days will result in the first two sessions ending on Wednesday and a break day. The next two sessions will start Friday again.
Therefore the sessions are even number of 18 and therefore will always end on a Wednesday
Answer:2.5 breaks
Step-by-step explanation:
Solve the triangle
Solve sides
Answer:
Step-by-step explanation:
Triangle RST is a right angle triangle.
From the given right angle triangle
RT represents the hypotenuse of the right angle triangle.
With 26 degrees as the reference angle,
ST represents the adjacent side of the right angle triangle.
RS represents the opposite side of the right angle triangle.
1) To determine RS, we would apply trigonometric ratio
Sin θ = opposite side/hypotenuse Therefore,
Sin 26 = RS/9.1
RS = 9.1Sin26 = 9.1 × 0.4384
RS = 4.0
2) To determine ST, we would apply trigonometric ratio
Cos θ = adjacent side/hypotenuse Therefore,
Cos 26 = ST/9.1
ST = 9.1Cos26 = 9.1 × 0.8988
ST = 8.1
3) The sum of the angles in a triangle is 180 degrees. Therefore,
∠R + 26 + 90 = 180
∠R = 180 - (26 + 90)
∠R = 64 degrees
Use the Gram-Schmidt process to find an orthonormal basis for the subspace of R4 spanned by the vectors (1, 0, 1, 1), (1, 0, 1, 0), (0, 0, 1, 1).
To find the orthonormal basis using the Gram-Schmidt process, we calculate the first vector by dividing the first given vector by its magnitude and normalize it. Then, we subtract the projection of each subsequent vector onto the previously found orthonormal vectors and normalize the resulting vector.
Explanation:To find an orthonormal basis for the subspace of R4 spanned by the given vectors using the Gram-Schmidt process, we will start by finding the first vector of the orthonormal basis. Let's call the given vectors v1, v2, and v3, respectively. The first vector of the orthonormal basis, u1, is equal to v1 divided by its magnitude, which is ||v1||. So, u1 = v1 / ||v1||. We can calculate ||v1|| as √(1^2 + 0^2 + 1^2 + 1^2) = √3.
Therefore, u1 = (1/√3, 0/√3, 1/√3, 1/√3).
Now, we need to find u2, the second vector of the orthonormal basis. To do this, we subtract the projection of v2 onto u1 from v2, then divide the result by its magnitude. We calculate the projection of v2 onto u1 as proj_u1(v2) = u1 * dot(u1, v2), where dot(u1, v2) represents the dot product of u1 and v2.
Finally, we subtract proj_u1(v2) from v2 to get v2' = v2 - proj_u1(v2), and then normalize v2' to get u2 = v2' / ||v2'||.
We can repeat this process to find u3, the third vector of the orthonormal basis. Subtract proj_u1(v3) and proj_u2(v3) from v3, then normalize the result to get u3 = v3' / ||v3'||.
Therefore, the orthonormal basis for the subspace spanned by the given vectors is (1/√3, 0/√3, 1/√3, 1/√3), (0, 0, 0, 1), and (-1/√3, 0/√3, 1/√3, 1/√3).
Learn more about Gram-Schmidt process here:https://brainly.com/question/30761089
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Graph the system of equations on your graph paper to answer the question.
y=−x+3
y=x+5
What is the solution to this system of equations?
( , )
Answer:
The solution of the two give equations is (-1,4)
Step-by-step explanation:
i) First equation is y = -x + 3
ii) Second equation is y = x + 5
iii) If we add the two equations we get 2y = 8 ∴ y = 4
iv) Substituting the value of y obtained in iii) in equation i) we get
4 = -x + 3 ∴ -x = 4 - 3 ∴ -x = 1 ∴ x = -1
v) substituting x = -1 and y = 4 in the second equation we see that the equation is satisfied.
In analyzing the recordings, what would you define as the unit for analysis? Why? How many data units (in rough estimates) are you likely to get based on this decision? Does the estimated number of data units seem adequate? Why or why not?
Answer:
a) The physicians since we want to measure about behaviors in the natural clinical settings from successful physicians. And the obervational unit would be the patients from these physicians.
b) They have in total 10 physicians who have been rated highly by patients but they use random sampling and they select just 5 physician-patient encounters from the 10 physicians
c) For this case based on the survey, we only have 10 doctors who have been highly qualified by the patients, so our goal is to analyze the information on these 10, and the sample size is 5. and that represent 50% of the original objective, so in this case we can say that this sample size would be sufficient to extrapolate the sample size information from 5 to the total number of doctors 10 of interest.
Step-by-step explanation:
Assuming this complete question: "Suppose you are interested in the behaviors of physicians that have high ratings of patient satisfaction. The research goal is to identify the behaviors in the natural clinical settings of these successful physicians so that these behaviors can be built into the curricula of medical preparation programs. The main data were collected by the video recording of five randomly selected physician-patient encounters from 10 physicians who have been rated highly by patients in a reliable satisfaction survey. In analyzing the recordings, what would you define as the unit for analysis? Why? How many data units (in rough estimates) are you likely to get based on this decision? Does the estimated number of data units seem adequate? Why or why not? "
In analyzing the recordings, what would you define as the unit for analysis? Why?
The physicians since we want to measure about behaviors in the natural clinical settings from successful physicians. And the obervational unit would be the patients from these physicians.
How many data units (in rough estimates) are you likely to get based on this decision?
They have in total 10 physicians who have been rated highly by patients but they use random sampling and they select just 5 physician-patient encounters from the 10 physicians
Does the estimated number of data units seem adequate? Why or why not?
For this case based on the survey, we only have 10 doctors who have been highly qualified by the patients, so our goal is to analyze the information on these 10, and the sample size is 5. and that represent 50% of the original objective, so in this case we can say that this sample size would be sufficient to extrapolate the sample size information from 5 to the total number of doctors 10 of interest.
The number of major earthquakes in a year is approximately normally distributed with a mean of 20.8 and a standard deviation of 4.5. a) Find the probability that in a given year there will be less than 21 earthquakes. b) Find the probability that in a given year there will be between 18 and 23 earthquakes.
Answer:
a) 51.60% probability that in a given year there will be less than 21 earthquakes.
b) 49.35% probability that in a given year there will be between 18 and 23 earthquakes.
Step-by-step explanation:
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:
[tex]\mu = 20.8, \sigma = 4.5[/tex]
a) Find the probability that in a given year there will be less than 21 earthquakes.
This is the pvalue of Z when X = 21. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{21 - 20.8}{4.5}[/tex]
[tex]Z = 0.04[/tex]
[tex]Z = 0.04[/tex] has a pvalue of 0.5160.
So there is a 51.60% probability that in a given year there will be less than 21 earthquakes.
b) Find the probability that in a given year there will be between 18 and 23 earthquakes.
This is the pvalue of Z when X = 23 subtracted by the pvalue of Z when X = 18. So:
X = 23
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{23 - 20.8}{4.5}[/tex]
[tex]Z = 0.71[/tex]
[tex]Z = 0.71[/tex] has a pvalue of 0.7611
X = 18
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{18 - 20.8}{4.5}[/tex]
[tex]Z = -0.62[/tex]
[tex]Z = -0.62[/tex] has a pvalue of 0.2676
So there is a 0.7611 - 0.2676 = 0.4935 = 49.35% probability that in a given year there will be between 18 and 23 earthquakes.
Final answer:
To find the probability of specific numbers of earthquakes occurring within a year using a normal distribution, one calculates the Z-scores for those numbers and looks up or calculates the corresponding probabilities.
Explanation:
The question involves finding probabilities related to the number of earthquakes in a year, which is modeled using a normal distribution. To find these probabilities, we'll use the mean μ = 20.8 and the standard deviation σ = 4.5 of the distribution.
a) Probability of less than 21 earthquakes
To find the probability of there being less than 21 earthquakes in a year, we calculate the Z-score for 21:
Z = (X - μ) / σ = (21 - 20.8) / 4.5 ≈ 0.04
Looking up this Z-score on a standard normal distribution table or using a calculator, we find the corresponding probability and note that it's slightly more than 0.5, indicating a little over a 50% chance.
b) Probability of 18 to 23 earthquakes
Finding the Z-scores for 18 and 23:
Z for 18 = (18 - 20.8) / 4.5 ≈ -0.62
Z for 23 = (23 - 20.8) / 4.5 ≈ 0.49
You then look up these Z-scores on a standard normal distribution table to find the probabilities for each and subtract the smaller from the larger to get the probability of having between 18 and 23 earthquakes in a year. This method shows that there's a significant chance, typically around 40% to 50%, though the specific value requires precise Z-score to probability conversion.
Ace Truck leases its 10-ft box truck at $30/day and $0.50/mi, whereas Acme Truck leases a similar truck at $25/day and $0.55/mi.
(a) Find the daily cost of leasing from each company as a function of the number of miles driven.
Answer:
Ace Truck
[tex]C(m) = 30 + 0.5*m[/tex]
Acme Truck
[tex]C(m) = 25 + 0.55*m[/tex]
Step-by-step explanation:
The cost function to lease a box truck from a company has the following format:
[tex]C(m) = F + a*m[/tex]
In which F is the fixed cost and a is the cost per mile m.
(a) Find the daily cost of leasing from each company as a function of the number of miles driven.
Ace Truck
$30/day and $0.50/mi. This means that [tex]F = 30, a = 0.50[/tex]. So
[tex]C(m) = 30 + 0.5*m[/tex]
Acme Truck
$25/day and $0.55/mi. This means that [tex]F = 25 a = 0.55[/tex]. So
[tex]C(m) = 25 + 0.55*m[/tex]
Let X denote the size of a bodily injury claim and Y denote the size of the corresponding property damage claim. Let Z1 = X + Y. From prior experience we know Var(X) = 144, Var(Y) = 64 and Var(X + Y) = 308. It is expected that bodily injury claims will rise 10% next year and property damage will rise by a fixed amount of 5. Let Z2 be the new trial of bodily injury and property damage. Compute Cov(Z1, Z2 ).
Final answer:
To compute the covariance between Z1 and Z2, we need to calculate the covariance between X and X, X and Y, Y and X, and Y and Y individually. Using the given variances and calculations, we can find Cov(Z1, Z2) = 308 + 0.1(144 + 2Cov(X, Y) + 64).
Explanation:
To compute the covariance between Z1 and Z2, we need to calculate the covariance between X and X, X and Y, Y and X, and Y and Y first.
Cov(X, X): Since Var(X) is given as 144, Cov(X, X) = Var(X) = 144Cov(X, Y): Cov(X, Y) = Cov(Y, X) because covariance is commutative. Also, Cov(X, Y) = Cov(Z1 - Y, Y) = Cov(Z1, Y) - Cov(Y, Y) = Cov(X + Y, Y) - Var(Y) = Cov(Z1, Y) - Var(Y) = Cov(Z1, Y) - 64Cov(Y, X): Since Cov(Y, X) = Cov(X, Y), we can use Cov(X, Y) from the previous step.Cov(Y, Y): Cov(Y, Y) = Var(Y) = 64Now, we can calculate Cov(Z1, Z2) using the following formula:
Cov(Z1, Z2) = Cov(X + Y, X + 0.1X + 5) = Cov(Z1, Z1 + 0.1X + 5) = Cov(Z1, Z1) + Cov(Z1, 0.1X) + Cov(Z1, 5) = Var(Z1) + 0.1Cov(Z1, X) + 0 = Var(X + Y) + 0.1Cov(Z1, X) + 0 = 308 + 0.1(Cov(X, X) + Cov(X, Y) + Cov(Y, X) + Cov(Y, Y)) + 0 = 308 + 0.1(144 + Cov(X, Y) + Cov(Y, X) + 64) + 0 = 308 + 0.1(144 + 2Cov(X, Y) + 64)
In a 2-sample z-test for two proportions, you find the following: sub(hat(p),1)
Answer:
[tex]z=\frac{0.32-0.36}{\sqrt{0.34(1-0.34)(\frac{1}{50}+\frac{1}{50})}}=-0.422[/tex]
So on this case the only option that satisfy the calculated statistic is:
z=-0.42
Step-by-step explanation:
Assuming this complete problem: "In a 2-sample z-test for two proportions, you find the following:
^P1 = 0.32, (n,1)=50
^P,2= 0.36, (n,2)=50
Find the test statistic you will use while executing this test:
z=-0.67 , z=±1.64 , z=-1.96 , z=0.34 , z=-0.42"
Solution to the problem
Data given and notation
[tex]n_{1}=50[/tex] sample 1 selected
[tex]n_{2}=50[/tex] sample 2 selected
[tex]p_{1}=0.32[/tex] represent the sample proportion for 1
[tex]p_{2}=0.36[/tex] represent the sample proportion for 2
z would represent the statistic (variable of interest)
[tex]p_v[/tex] represent the value for the test (variable of interest)
We need to apply a z test to compare proportions, and the statistic is given by:
[tex]z=\frac{\hat p_{1}-\hat p_{2}}{\sqrt{\hat p (1-\hat p)(\frac{1}{n_{1}}+\frac{1}{n_{2}})}}[/tex] (1)
Or equivalently:
[tex]z=\frac{\hat p_{2}-\hat p_{1}}{\sqrt{\hat p (1-\hat p)(\frac{1}{n_{1}}+\frac{1}{n_{2}})}}[/tex] (1)
Where [tex]\hat p=\frac{X_{1}+X_{1}}{n_{1}+n_{1}}=\frac{\hat p_1 +\hat p_2}{2}=\frac{0.32+0.36}{2}=0.34[/tex]
Calculate the statistic
Replacing in formula (1) the values obtained we got this:
[tex]z=\frac{0.32-0.36}{\sqrt{0.34(1-0.34)(\frac{1}{50}+\frac{1}{50})}}=-0.422[/tex]
So on this case the only option that satisfy the calculated statistic is:
z=-0.42
A population consists of the following N = 5 scores: 0, 6, 4, 3, and 12.
(a) Compute µ and σ for the population.
(b) Find the z-score for each score in the population.
(c) Transform the original population into a new population of N = 5 scores with a mean of µ = 100 and a standard deviation of σ = 20.
Answer:a) μ = 5 and σ = 16
b) z-score are -0.3125, 0.0625, -0.0625, -0.125, 0.4375
c) New population of N=5 scores are 93.75, 101.25, 98.75, 97.5, 108.75
Step-by-step explanation:
The detailed explanation can be found in the attached pictures
The new population of N = 5 scores with a mean of µ = 100 and a standard deviation of σ = 20 are 125, 105, 95, 90 and 135
(a) Compute µ and σ for the population.
The dataset is given as:
0, 6, 4, 3, and 12.
The mean is calculated as:
[tex]\mu = \frac{\sum x}n[/tex]
So, we have:
[tex]\mu = \frac{0 + 6 + 4 + 3 + 12}5[/tex]
[tex]\mu = 5[/tex]
The standard deviation is calculated as:
[tex]\sigma = \sqrt{\frac{\sum(x - \bar x)^2}n}[/tex]
This gives
[tex]\sigma = \sqrt{\frac{(0 - 5)^2 + (6- 5)^2 + (4- 5)^2 + (3- 5)^2 + (12- 5)^2}5[/tex]
[tex]\sigma = \sqrt{\frac{80}5[/tex]
[tex]\sigma = \sqrt{16[/tex]
[tex]\sigma = 4[/tex]
Hence, the values of μ and σ are μ = 5 and σ = 4
(b) The z-scores
This is calculated as:
[tex]z = \frac{x - \mu}{\sigma}[/tex]
When x = 0, 6, 4, 3, and 12.
We have:
[tex]z = \frac{0 - 5}{4} = 1.25[/tex]
[tex]z = \frac{6 - 5}{4} = 0.25[/tex]
[tex]z = \frac{4 - 5}{4} = -0.25[/tex]
[tex]z = \frac{3 - 5}{4} = -0.5[/tex]
[tex]z = \frac{12 - 5}{4} = 1.75[/tex]
Hence, the z-scores are 1.25, 0.25, -0.25, -0.5 and 1.75
(c) Transform the new population
We have:
N = 5, µ = 100 and σ = 20.
In (b), we have:
[tex]z = \frac{x - \mu}{\sigma}[/tex]
Make x the subject
[tex]x = \mu + z\sigma[/tex]
This gives
[tex]x_i = \mu + z_i\sigma[/tex]
So, we have:
[tex]x_1 = 100 + 1.25* 20 = 125[/tex]
[tex]x_2 = 100 + 0.25* 20 = 105[/tex]
[tex]x_3 = 100 - 0.25* 20 = 95[/tex]
[tex]x_4 = 100 - 0.5* 20 = 90[/tex]
[tex]x_5 = 100 + 1.75* 20 = 135[/tex]
Hence, the new population of N = 5 scores with a mean of µ = 100 and a standard deviation of σ = 20 are 125, 105, 95, 90 and 135
Read more about z-scores at:
https://brainly.com/question/16313918
A hypothesis is _____ Question 20 options: a proven scientific fact an instrument that is used to examine environmental conditions a testable proposition that explains an observed phenomenon or answers a question the design of an experiment that can be used in scientific inquiry a prediction about something that has not yet been observed
The options are properly listed below:
A. a proven scientific fact
B. an instrument that is used to examine environmental conditions
C. a testable proposition that explains an observed phenomenon or answers a question
D. the design of an experiment that can be used in scientific inquiry
E. a prediction about something that has not yet been observed
ANSWER:
C. a testable proposition that explains an observed phenomenon or answers a question
EXPLANATION:
HYPOTHESIS is a proposed explanation for an observable fact, but that cannot satisfactorily be explained with the available scientific theories. It is based on the information acquired from a primary source or data collected during a scientific activity.
Also, for a hypothesis to be a scientific hypothesis, the scientific method requires that it is testable.
It is also a trial solution to a question.
Hypothesis can be provisionally accepted as a starting point for further research.
If Ms. P wants to withdraw $900 from an account earning 4% average annual interest rate at the start of each year for 7 years, how much must she have in the account today?
Answer:
Amount he must have in his account today is $5,617.92
Step-by-step explanation:
Data provided in the question:
Regular withdraw amount = $900
Average annual interest rate, i = 4% = 0.04
Time, n = 7 years
Now,
Present Value = [tex]C \times\left[ \frac{1-(1+i)^{-n}}{i} \right] \times(1 + i)[/tex]
here,
C = Regular withdraw amount
Thus,
Present Value = [tex]C \times\left[ \frac{1-(1+i)^{-n}}{i} \right] \times(1 + i)[/tex]
Present Value = [tex]900 \times\left[ \frac{1-(1+0.04)^{-7}}{ 0.04 } \right] \times(1 + 0.04)[/tex]
Present Value = [tex]936 \times\left[ \frac{1 - 1.04^{-7}}{ 0.04} \right][/tex]
Present Value = [tex]936 \times\left[ \frac{1 - 0.759918}{ 0.04} \right][/tex]
Present Value = 936 × 6.00205
or
Present Value = $5,617.92
Hence,
Amount he must have in his account today is $5,617.92
The probability of success in each of the 58 identical engine tests is p = 0.92. What is the mean of this binomial distribution?
Answer:
53.36
Step-by-step explanation:
The mean of binomial distribution is calculated by multiplying number of trials to probability of success. It can be denoted as
E(x)=mean=np
Where n is the fixed number of trails and p is the probability of success.
Here, n=58 and p=0.92
E(x)=np
E(x)=58*0.92
E(x)=53.36
So, the mean of the given binomial distribution is 53.36.
The mean of this binomial distribution is 53.36.
Explanation:The mean of a binomial distribution can be calculated using the formula µ = np, where µ represents the mean, n is the number of trials, and p is the probability of success in each trial.
In this case, the problem mentions 58 identical engine tests with a probability of success, p, being 0.92. Therefore, the mean of this binomial distribution would be µ = 58 * 0.92 = 53.36.
The doctor has told Cal O'Ree that during his ten weeks of working out at the gym, he can expect each week's weight loss to be $1\%$ of his weight at the end of the previous week. His weight at the beginning of the workouts is $244$ pounds. How many pounds does he expect to weigh at the end of the ten weeks?
Cal's expected weight after 10 weeks can be calculated using the exponential decay formula, with his initial weight being 244 lbs, the decay rate being 1% (or 0.01), and time being 10 weeks. The formula then becomes W = 244*(1 - 0.01)^10.
Explanation:Cal O'Ree's weight loss over the span of 10 weeks can be calculated using the principles of exponential decay. In this context, The doctor's statement implies that Cal's weight decreases by 1% each week - this is the decay rate. The solution to this kind of problem lies in the formula for exponential decay: W = P*(1 - r)^t, where P is the initial quantity (in this case, weight), r is the decay rate, and t is the time. For Cal, P = 244 pounds, r = 0.01, and t = 10 weeks.
After substituting these values into the formula, we get: W = 244*(1 - 0.01)^10. Calculating the expression gives us the weight that Cal is expected to have after 10 weeks of working out following the doctor's prognosis.
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What proportion of fire loads are less than 600? At least 1200? (Round your answers to three decimal places.) less than 600 at least 120
Answer:
a) For this case we see that the cumulative % for 600 is 77.1% so then we will have 0.771 of the values below 600
b) For this case we know that the cumulative percent for 1200 is 98.2% so then the percentage above would be 100-98.2 = 1.8%, so then the proportion above 1200 would be 0.018.
c) For this case we can add the percentages obtained from the previous parts and we got : 77.1% +1.8% = 78.9% and then the proportion that are less than 600 and at least 100 would be 0.789
Step-by-step explanation:
Assuming the cumulative percentages in the figure attached.
What proportion of fire loads are less than 600?
For this case we see that the cumulative % for 600 is 77.1% so then we will have 0.771 of the values below 600
What proportion of fire loads are At least 1200?
For this case we know that the cumulative percent for 1200 is 98.2% so then the percentage above would be 100-98.2 = 1.8%, so then the proportion above 1200 would be 0.018.
What proportion of fire loads are less than 600 at least 120?
For this case we can add the percentages obtained from the previous parts and we got : 77.1% +1.8% = 78.9% and then the proportion that are less than 600 and at least 100 would be 0.789
A chemist needs to mix a 39% salt solution with a 70% salt solution to make 40 liters of a 55% salt solution. How many liters of each solution should the chemist mix to get the desired result?
Solution with 39% salt:
.
Solution with 70% salt:
Thanks a ton!! :)
Step-by-step explanation:
If x is the volume of 39% solution, and y is the volume of 70% solution, then:
x + y = 40
0.39x + 0.70y = 0.55(40)
Solve the system of equations.
0.39x + 0.70(40 − x) = 0.55(40)
0.39x + 28 − 0.70x = 22
6 = 0.31x
x = 19.4
y = 20.6
The chemist needs 19.4 liters of 39% solution and 20.6 liters of 70% solution.
A person has a 35 percent chance of winning on a scratch-off lottery ticket. What is the probability she first wins of the sixth ticket? (0.65)3 (0.35) (0.65)3 (0.35) (0.35)3 (0.65) () (0.35) (0.65) 0.35
Final answer:
To calculate the probability of winning on the sixth ticket, multiply the probability of not winning on the first five tickets by the probability of winning on the sixth ticket.
Explanation:
To calculate the probability of winning on the sixth ticket, we multiply the probability of not winning on the first five tickets (0.65)^5 by the probability of winning on the sixth ticket (0.35). Here's the step-by-step calculation:
Probability of not winning on the first five tickets: (0.65)^5
Probability of winning on the sixth ticket: 0.35
Overall probability of first winning on the sixth ticket: (0.65)^5 * 0.35Therefore, the probability of first winning on the sixth ticket is equal to (0.65)^5 * 0.35.
Let A and B be subsets of R. (a) If x ∈ (A ∩ B)c, explain why x ∈ Ac ∪ Bc. This shows that (A ∩ B)c ⊆ Ac ∪ Bc. 12 Chapter 1. The Real Numbers (b) Prove the reverse inclusion (A ∩ B)c ⊇ Ac ∪ Bc, and conclude that (A ∩ B)c = Ac ∪ Bc. (c) Show (A ∪ B)c = Ac ∩ Bc by demonstrating inclusion both ways.
Answer:
answer is -3 just subtract 4 from each side
Step-by-step explanation:
Answer:
B
Step-by-step explanation:
B ⊂ A
Hope it helps!
Find the area of the parallelogram with vertices Ps1, 0, 2d, Qs3, 3, 3d, Rs7, 5, 8d, and Ss5, 2, 7d.
To find the area of a parallelogram, you can use the cross product of two vectors created from the vertices. The magnitude of the resulting vector represents the area of the parallelogram. Ensure to put an absolute value on the final result.
Explanation:The subject of this question is geometry, specifically finding the area of a parallelogram given the vertices. You can calculate the area of a parallelogram using the cross product of two vectors. First, create two vectors from the given vertices, for example, PQ = Q - P and PR = R - P. For your question, let's take P as s1, 0, 2d, Q as s3, 3, 3d, and R as s7, 5, 8d. So, PQ = s2, 3, 1d and PR = s6, 5, 6d. The cross product of these two vectors would give a vector perpendicular to both, whose magnitude represents the area of the parallelogram spanned by the vectors PQ and PR. The magnitude (or length) of a vector ABC = sA, B, Cd is calculated as √(A² + B² + C²).
Using these formulas and calculations, you should be able to find the area of your parallelogram. Remember to put absolute value on the final answer as area cannot be negative.
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What are the hypotheses for testing to see if a correlation is statistically significant?
Answer:
Step-by-step explanation:
For testing of significance of correlation coefficient denoted by r, we create hypotheses in three ways
They are one tailed, two tailed. One tailed can be stated as right tailed and also left tailed.
The null hypothesis would normally be as r=0
Verbally we can say this there is no association between the dependent and independent variable (linear)
Against this alternate hypothesis is created as
either r not equal to 0
or r>0 or r<0
If r not equal to 0, we say two tailed hypothesis test
If r>0 is alternate hypothesis, it is right tailed test
If r<0 is alternate hypothesis, then it is left tailed test.
Carlos will buy coffee and hit chocolate for his co-workers. Each cup of coffee costs $2.25 and each cup of hit chocolate costs $1.50. If he pays a total of $15.75 for 8 cups, how many of each did he buy?
Answer: he bought 5 cups of coffee.
He bought 3 cups of hit chocolate
Step-by-step explanation:
Let x represent the number cups of coffee that he bought.
Let y represent the the number cups of of hit chocolate that he bought.
He bought a total of 8 cups coffee and hit chocolate. This means that
x + y = 8
Each cup of coffee costs $2.25 and each cup of hit chocolate costs $1.50. If he pays a total of $15.75 for 8 cups, it means that
2.25x + 1.5y = 15.75 - - - - - - - - - - - - 1
Substituting x = 8 - y into equation 1, it becomes
2.25(8 - y) + 1.5y = 15.75
18 - 2.25y + 1.5y = 15.75
- 2.25y + 1.5y = 15.75 - 18
- 0.75y = - 2.25
y = - 2.25/- 0.75
y = 3
Substituting y = 3 into x = 8 - y, it becomes
x = 8 - 3 = 5
Write the ratios for sine C cosine C and tangent C
Answer:
sin C = 7/27, cos C = 24/27 and tan C = 7/24
Step-by-step explanation:
sin C = opposite/hypotenuse
= 7/27
cos C = adjacent/hypotenuse
= 24/27
tan C = opposite/ adjacent
= 7/24
Answer:
sin c - 25/7
cos c - 7/24
tan c - 25/24
Step-by-step explanation:
Find the arc length of the given curve between the specified points.
y = x3 12 + 1 x from 1, 13 12 to 4, 67 12
The value of L is approximately 2.609.
Given curve [tex]y = \frac{x^3}{12} + \frac{1}{x}[/tex], from x = 1 to x = 2.
The arc length of a curve defined by a function y = f(x) from x = a to x = b can be calculated using the arc length formula:
[tex]L = \int_{a}^{b} \sqrt{1 + (f'(x))^2} dx[/tex]
To calculated the value of L, to find the derivative f'(x) and substitute it into the arc length formula.
First, let's find the derivative of y with respect to x:
[tex]f'(x) = \dfrac{d}{dx} (\dfrac{x^3}{12} + \dfrac{1}{x})\\f'(x) = \dfrac{1}{4}x^2 - \dfrac{1}{x^2}[/tex]
Now, we can substitute this derivative into the arc length formula:
[tex]L = \int_{1}^{2} \sqrt{1 + (\frac{1}{4}x^2 - \frac{1}{x^2})^2} dx[/tex]
Now, represent this arc length integral:
[tex]L = \int_{1}^{2} \sqrt{1 + \left(\frac{1}{4}x^2 - \frac{1}{x^2}\right)^2} dx[/tex]
Expanding the square inside the square root:
[tex]L = \int_{1}^{2} \sqrt{1 + \left(\frac{1}{16}x^4 - \frac{1}{2} + \frac{1}{x^4}\right)} dx[/tex]
Combining the terms inside the square root:
[tex]L = \int_{1}^{2} \sqrt{\frac{1}{16}x^4 + \frac{1}{2} - \frac{1}{x^4} + 1} dxL = \int_{1}^{2} \sqrt{\frac{1}{16}x^4 + \frac{1}{x^4} + \frac{3}{2}} dx[/tex]
Now, let's integrate this expression:
[tex]L = \int_{1}^{2} \sqrt{\frac{1}{16}x^4 + \frac{1}{x^4} + \frac{3}{2}} dx[/tex]
So, the value of L is approximately 2.609.
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Complete question:
Find the arc length of the curve [tex]Y= ((x^3)/12)) + 1/x[/tex] from x = 1 to x = 2.
Arc Length [tex]\[Arc\ Length = \int_1^2 \sqrt{1 + \frac{1}{x^4}} \, dx\][/tex]
To find the arc length of the curve [tex]\(y = \frac{3}{12} + \frac{1}{x}\)[/tex] on the interval [tex]\([1, 2]\)[/tex], you can use the arc length formula for a function [tex]\(y = f(x)\)[/tex] on the interval [tex]\([a, b]\)[/tex]:
[tex]\[Arc\ Length = \int_a^b \sqrt{1 + (f'(x))^2} \, dx\][/tex]
First, calculate the derivative of the function [tex]\(y = \frac{3}{12} + \frac{1}{x}\):\[y' = 0 - \frac{1}{x^2} = -\frac{1}{x^2}\][/tex]
Now, we can set up the integral:
[tex]\[Arc\ Length = \int_1^2 \sqrt{1 + \left(-\frac{1}{x^2}\right)^2} \, dx\][/tex]
Simplify the expression inside the square root:
[tex]\[Arc\ Length = \int_1^2 \sqrt{1 + \frac{1}{x^4}} \, dx\][/tex]
This integral does not have a simple closed-form solution, so you may need to use numerical methods or a calculator to approximate the value of the arc length.
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The probable question can be: Find the arc length of the curve Y = ((3)/12)) + 1/ from x = 1 to x = 2.
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In an election in a small town, everybody voted for one of the three candidates. The winner received
8392 votes, and the second-place candidate got 7480 votes. If 20900 people voted in the election,
how many people voted for the third candidate?
PLEASE SHOW WORK!
Answer:
The answer to your question is 5028 votes
Step-by-step explanation:
Data
Winner 8392 votes
Second-place = 7480 votes
Total votes = 20900
Third candidate = ?
Process
1.- Write an equation
Total votes = Winner + Second-place + Third-place
Solve for Third-place
Third-place = Total votes - Winner - Second-place
2.- Substitution
Third-place = 20900 - 8392 - 7480
3.- Simplification
Third-place = 20900 - 15872
4.- Result
Third-place = 5028 votes
Answer:
5028
Step-by-step explanation:
If everyone in the town voted for 3 candidates and the total vote is 20900, then
a + b + c = 20900
If stands for the first contestant, b for the second contestant and c for the last contestant.
If a = 8392
b = 7480
c = 20900-(a+b)
c = 20900-15872
c = 5028
5th grade math lesson 7.9 a vet weighs 2 puppies. The small puppy weighs 4 1/2 pounds. The large puppy weighs 42/3 times as much as the small puppy. How much does the small puppy weigh
The large puppy weighs 4 1/2 x 42/3 pounds.
4 1/2 x 42/3 = 9/2 x 42/3 = 63 pounds
answer: 63 pounds for the large puppy
Answer:the large puppy weighs 63 pounds.
Step-by-step explanation:
A vet weighs 2 puppies. The small puppy weighs 4 1/2 pounds. Converting 4 1/2 pounds to improper fraction, it becomes 9/2 pounds.
The large puppy weighs 42/3 times as much as the small puppy. This means that the number of pounds that the large puppy weighs would be
42/3 × 9/2 = 63
Find the height of the ramp and the length of the base of the ramp
Answer:
x = 6.1 and y = 12.6
Step-by-step explanation:
sin 26 = x/14
x = 14sin26
x = 6.14
x= 6.1
cos 26 = y/14
y = 14cos26
y = 12.58
y = 12.6
Answer:the height of the ramp is 6.1ft
the length of the base of the ramp is 12.6 ft
Step-by-step explanation:
Triangle ABC is a right angle triangle.
The length of the ramp represents the hypotenuse of the right angle triangle.
With 26 degrees being the reference angle,
The opposite side of the right angle triangle = x
The adjacent side of the right angle triangle = y
To determine x, we would apply the Sine trigonometric ratio.
Sin θ = opposite side/hypotenuse
Sin 26 = x/14
x = 14Sin26 = 14 × 0.4384 =
x = 6.1
To determine y, we would apply the Cosine trigonometric ratio.
Cos θ = adjacent side /hypotenuse
Cos 26 = y/14
x = 14Cos26 = 14 × 0.8988 =
x = 12.6
Find the missing lengths:
OK=1 and OL=3, find KH and LH.
Answer:
KH = 2 and LH = 2√3
Step-by-step explanation:
Using Euclidean theorem for the right triangle.
∵ ΔLHK is a right triangle at H
OK = 1 , OL = 3
KL = KO + OL = 1 + 3 = 4
KH² = KO * KL = 1 * 4 = 4
KH = √4 = 2
And LH² = LO * LK = 3 * 4 = 12
∴ LH = √12 = 2√3