CNNBC recently reported that the mean annual cost of auto
insurance is 1016 dollars. Assume the standard deviation is 242
dollars. You take a simple random sample of 89 auto insurance
policies.
Find the probability that a single randomly selected value is at
least 980 dollars.
P(X > 980) =
Find the probability that a sample of size n=89n=89 is randomly
selected with a mean that is at least 980 dollars.
P(M > 980) =
Enter your answers as numbers accurate to 4 decimal places.
In: Math
Mean=33,820.21
Standard Deviation=22,948.45
n=52
Calculate a 99% confidence interval, assuming that sigma is unknown.
In: Math
A study was performed to test a new treatment for autism in children. In order to test the new method,
parents of children with autism were asked to volunteer for the study in which 9 parents volunteered their
children for the study. The children were each asked to complete a 20 piece puzzle. The time it took to
complete the task was recorded in seconds. The children then received a treatment (20 minutes of yoga) and
were asked to complete a similar but different puzzle. The data from the study is below:
Child Before After
1 85 75
2 70 60
3 40 50
4 65 40
5 80 20
6 75 65
7 55 40
8 20 25
9 70 30
Part A
Calculate the statistic S for a signed rank test by hand showing the final table with the absolute differences,
the signs, and the ranks. Also, show your calculation of the z-statistic (standardized S statistic).
Part B
Verify your calculation in both SAS and R. Simply cut and paste your code and relevant output.
Part C
Using all the information from parts A and B, conduct the six step hypothesis test using your calculations
from above to test the claim that the yoga treatment was effective in reducing the time to finish the puzzle.
Part D
Use SAS to conduct a six step hypothesis test using a paired t-test to test the claim that the yoga treatment
was effective in reducing the time to finish the puzzle.
Part E
Verify your calculations in R. Simply cut and paste your code and relevant output.
Part F
Which test (the sign test, the signed rank test, or the paried t-test) do you think is most appropriate for this
data? Why?
In: Math
Consider the accompanying data on plant growth after the application of different types of growth hormone. 1: 13 16 7 13 2: 20 12 19 16 3: 19 16 20 16 4: 7 11 18 9 5: 6 10 15 9 (a) Perform an F test at level α = 0.05. State the appropriate hypotheses. H0: μ1 ≠ μ2 ≠ μ3 ≠ μ4 ≠ μ5 Ha: all five μi's are equal H0: μ1 ≠ μ2 ≠ μ3 ≠ μ4 ≠ μ5 Ha: at least two μi's are equal H0: μ1 = μ2 = μ3 = μ4 = μ5 Ha: all five μi's are unequal H0: μ1 = μ2 = μ3 = μ4 = μ5 Ha: at least two μi's are unequal Calculate the test statistic. (Round your answer to two decimal places.) f = What can be said about the P-value for the test? P-value > 0.100 0.050 < P-value < 0.100 0.010 < P-value < 0.050 0.001 < P-value < 0.010 P-value < 0.001 State the conclusion in the problem context. Fail to reject H0. There appears to be a difference in the average growth of at least two groups. Reject H0. There appears to be a difference in the average growth of at least two groups. Reject H0. There does not appear to be a difference in the average growth. Fail to reject H0. There does not appear to be a difference in the average growth. (b) What happens when Tukey's procedure is applied? (Round your answer to two decimal places.) w = Which means differ significantly from one another? (Select all that apply.) x1. and x2. x1. and x3. x1. and x4. x1. and x5. x2. and x3. x2. and x4. x2. and x5. x3. and x4. x3. and x5. x4. and x5. There are no significant differences. Are Tukey's method and the F test in agreement? Yes No
In: Math
Use a normal approximation to find the probability of the indicated number of voters. In this case, assume that 146 eligible voters aged 18-24 are randomly selected. Suppose a previous study showed that among eligible voters aged 18-24, 22% of them voted.
Probability that fewer than 37 voted
In: Math
Are older men shorter than younger men? According to a national report, the mean height for U.S. men is 69.4 inches. In a sample of 119 men between the ages between of 60 and 69 and, the mean height was 69.3 inches. Public health officials want to determine whether the mean height for older men is less than the mean height of all adult men. Assume the population standard deviation to be 2.58. Use the a=0.05 level of significance and the-value method with the table.
In: Math
A researcher wanted to test the claim that members of college sororities have grade point averages (GPA) above the mean GPA of 2.64 for all college students. She collected a random sample of 50 members of college sororities that had a mean GPA of 2.82. It is known that the population standard deviation for GPA is 0.90. Conduct a hypothesis test for this situation at the 0.05 level of significance and indicate what the researcher should conclude.
In: Math
For the following, indicate whether you should use a one sample t-test, paired t-test, or two sample t-test and whether you have chosen a one-sided or two-sided alternate hypothesis:
A) Do macroeconomics students at Vanderbilt score significantly higher on the Math SAT than the national average?
My Answer: One sample t-test, one tailed
B) Do macroeconomics students at Vanderbilt score significantly higher on the Verbal SAT than the national average?
My answer: One sample t-test, one tailed
C) Report a 95 percent confidence interval for the true mean Math SAT score. Do 95 percent of students have Math SAT scores that fall within this interval? Explain your answer.
My answer: One sample t-test, one tailed
D) Is there a statistically significant difference between the Verbal and Math scores of macroeconomics students at Vanderbilt?
My Answer: Paired t-test, two tailed
E) Is there a statistically significant difference between the performances of males and females on the Verbal SAT? Construct a 95 percent confidence interval for the difference. Does it include zero? Relate this to the conclusion of your test.
My Answer: Two sample t-test, two tailed
F) Is there a statistically significant difference between the performances of males and females on the Math SAT? Construct a 95 percent confidence interval for the difference. Does it include zero? Relate this to the conclusion of your test.
My answer: Two sample t-test, two tailed
G) Is there a statistically significant difference between the freshman GPAs of males and females? Construct a 95 percent confidence interval for the difference. Does it include zero? Relate this to the conclusion of your test.
My answer: Two sample t-test, two tailed
Could someone please double check my answers and if any are incorrect, explain to me where I went wrong? Thanks!
In: Math
Suppose there is a linear association between crime rate and percentage of high school graduates.
a) State the full and reduced model
b)Obtain SSE(F), SSE(R), df(F), fd(R), test statistics F for the general linear test and decision rule.
crime rate, high school grad %
8487 74 8179 82 8362 81 8220 81 6246 87 9100 66 6561 68 5873 81 7993 74 7932 82 6491 75 6816 82 9639 78 4595 84 5037 82 4427 79 6226 78 10768 73 8335 77 12311 65 10104 77 10503 76 7562 79 8593 79 7133 78 10205 84 14016 78 5959 81 3764 89 4297 85 7562 77 4844 74 5777 80 3599 84 3219 88 11187 75 2105 77 6650 78 11371 61 4517 91 7348 83 5696 77 4995 85 9248 70 6860 88 9776 80 4280 82 11154 82 3442 82 9674 70 7309 64 4530 79 4017 83 7122 77 5689 76 6109 80 3343 84 5029 82 4330 81 5425 74 8769 81 6880 76 6538 78 6521 78 9423 79 9697 83 3805 79 3134 83 3433 81 2979 84 6836 64 5804 67 7986 75 10994 73 11322 77 8937 64 8807 75 11087 80 10355 83 7858 85 3632 91 8040 88 6981 83 7582 76
In: Math
When 41 people are used the Weight Watchers diet for one year, their weight losses had a standard deviation of 4.9lb. Use a 0.01 significance level to test the claim that the amounts of weight loss have a standard deviation equal to 6.0lb, which appears to be the standard deviation for the amounts of weight loss with the Zone diet. Write your assumptions before you conduct hypothesis testing.
In: Math
Below you have a payoff table for a set of decisions that are under consideration.
States of Nature
Alternative Low High
Option A 10 15
Option B 12 13
Option C 13 10
Choose the correspondence equation line for option A, B, and C:
Y= -5x+15x
Y=3x+10
Y=-X+13
In: Math
In a study of computer use, 1000 randomly selected Canadian Internet users were asked how much time they spend using the Internet in a typical week. The mean of the sample observations was 12.9 hours.
(a) The sample standard deviation was not reported, but suppose that it was 6 hours. Carry out a hypothesis test with a significance level of 0.05 to decide if there is convincing evidence that the mean time spent using the Internet by Canadians is greater than 12.7 hours. (Use a statistical computer package to calculate the P-value. Round your test statistic to two decimal places and your P-value to three decimal places.)
t= P-value =
State the conclusion in the problem context.
a. Reject H0. We have convincing evidence that the mean weekly time spent using the Internet by Canadians is greater than 12.7 hours.
b. Do not reject H0. We do not have convincing evidence that the mean weekly time spent using the Internet by Canadians is greater than 12.7 hours.
c. Do not reject H0. We have convincing evidence that the mean weekly time spent using the Internet by Canadians is greater than 12.7 hours.
d. Reject H0. We do not have convincing evidence that the mean weekly time spent using the Internet by Canadians is greater than 12.7 hours.
(b) Now suppose that the sample standard deviation was 2 hours. Carry out a hypothesis test with a significance level of 0.05 to decide if there is convincing evidence that the mean time spent using the Internet by Canadians is greater than 12.7 hours. (Use a statistical computer package to calculate the P-value. Round your test statistic to two decimal places and your P-value to three decimal places.)
t= P-value =
State the conclusion in the problem context.
a. Reject H0. We have convincing evidence that the mean weekly time spent using the Internet by Canadians is greater than 12.7 hours.
b. Do not reject H0. We do not have convincing evidence that the mean weekly time spent using the Internet by Canadians is greater than 12.7 hours.
c. Reject H0. We do not have convincing evidence that the mean weekly time spent using the Internet by Canadians is greater than 12.7 hours.
d. Do not reject H0. We have convincing evidence that the mean weekly time spent using the Internet by Canadians is greater than 12.7 hours.
(c) Explain why the hypothesis tests resulted in different conclusions for part (a) and part (b).
a.The larger standard deviation means that you can expect less variability in measurements and smaller deviations from the mean. This explains why H0 is rejected when the sample standard deviation is 6, but not when the sample standard deviation is 2.
b. The smaller standard deviation means that you can expect more variability in measurements and greater deviations from the mean. This explains why H0 is rejected when the sample standard deviation is 2, but not when the sample standard deviation is 6.
c. The smaller standard deviation means that you can expect less variability in measurements and smaller deviations from the mean. This explains why H0 is rejected when the sample standard deviation is 6, but not when the sample standard deviation is 2.
d. The larger standard deviation means that you can expect more variability in measurements and greater deviations from the mean. This explains why H0 is rejected when the sample standard deviation is 2, but not when the sample standard deviation is 6.
In: Math
1. A basketball player makes 54% of his shots during the regular
season games.
a) To simulate whether a shot hits or misses you could assign
random digits as
follows:
(i) One digit simulates one shot; 1 and 5 are a make, other digits
are a miss.
(ii) One digit simulates one shot; odd digits are a make and even
digits are a miss.
(iii) Two digits simulate one shot; 00 to 54 are a make and 55 to
99 are a miss.
(iv) Two digits simulate one shot; 00 to 53 are a make and 54 to 99
are a miss.
(v) Two digits simulate one shot; 01 to 54 are a make and 55 to 99
are a miss.
b) Using your choice in part (a) and these random digits below,
simulate 10 shots.
12734 75390 20867 27513
c) Compute estimated probability:
In: Math
Toyota’s marketing department is in the process of creating an ad meant to highlight the fuel efficiency of its Camry model compared to its Avalon model. Toyota knows that based on their production process, the miles per gallon (mpg) of both the Camry and the Avalon follow a normal distribution with the Camry having a standard deviation of 1.5 mpg and the Avalon having a standard deviation of 3.6 mpg. Toyota takes a sample of 50 Camry models and 60 Avalon models and finds that the Camry has a mean mpg of 31 while the Avalon has a mean mpg of 29.5 mpg. Toyota would like to know if there is sufficient evidence, at the alpha=0.01 level, to conclude that the Camry has a higher mpg than the Avalon. Answer the following questions.
In: Math
Companies who design furniture for elementary school classrooms produce a variety of sizes for kids of different ages. Suppose the heights of kindergarten children can be described by a Normal model with a mean of 39.2
inches and standard deviation of
1.9inches.
a) What fraction of kindergarten kids should the company expect to be less than
33 inches tall?About blank % of kindergarten kids are expected to be less than 33 inches tall.
(Round to one decimal place as needed.)
b) In what height interval should the company expect to find the middle 80% of kindergarteners?The middle 80% of kindergarteners are expected to be between what inches and what inches.
(Use ascending order. Round to one decimal place as needed.)
c) At least how tall are the biggest 30% of kindergarteners?The biggest 30% of kindergarteners are expected to be at least ? inches tall.
(Round to one decimal place as needed.)
In: Math