# stats

posted by
**sandra** on
.

I am having a bit of trouble with the top half of the questions. I have an answer below for questions 5-10, is there anyway you can check those answers and help me with the rest I am having trouble with. Thank you.

1. The area to the right of 1.93 under Student's t-curve with 11 degrees of freedom is

a. Between 5% and 2.5%

b. More than 95%

c. Between 25% and 10%

d. Less than 1%

2. The area to the left of -1.5 under Student's curve with 9 degrees of freedom is

a. Between 25% and 10%

b. Between 10% and 5%

c. Exactly 7.5%

d. Between 95% and 90%

3. The area to the left of 1.25 under Student's t-curve with 20 degrees of freedom is

a. Less than 10%

b. Between 25% and 10%

c. More than 75%

d. More than 90%

4. You should use a t-test when which of the following apply? (Choose all of the correct responses.)

a. The size of the sample (draws from the box) is less than or equal to 25.

b. Only for hypothesis tests about the average.

c. For hypothesis tests about either the percentage or the average.

d. For every hypothesis test where you know the standard deviation of the box.

Use the information below to answer questions 5-7.

Commuter students at a certain college claim that the average distance they have to commute to campus is less than 26 miles per day. A random sample of 16 commuter students was surveyed and yielded an average distance of 29 miles and a SD of 8 miles. We want to test the hypothesis that the students' claim is correct.

5. The test statistic for this hypothesis test is closest to:

a. 0.5

b. 1.0

c. 1.5

d. 3

I think it is C

6. The p-value for this hypothesis is:

a. between 25% and 10%

b. between 10% and 5%

c. between 5% and 2.5%

d. between 1% and 0.5%

I think it is B

7. Based on the p-value, you can conclude that:

a. It is not plausible that the average commute is 29 miles per day.

b. It is plausible that the average commute is 29 miles per day.

c. It is not plausible that the average commute is less than 26 miles per day.

d. It is plausible that the average commute is less than 26 miles per day.

I think it is D

Use the information below to answer questions 8-10.

An advertising agency would like to create an advertisement for a fast-food restaurant claiming that the average waiting time from ordering to receiving your order at the restaurant is less than 5 minutes. The agency measured the time from ordering to deliver of order for 25 customers and found that the average time was 4.7 minutes with an SD+ of .6 minutes. Test the following hypotheses: Null: Waiting time is 5 minutes or more Alternative: Waiting time is less than 5 minutes

8. The test statistic is closest to:

a. -0.5

b. -2.5

c. 3.03

d. 12.5

I think it is B

9. The p-value is:

a. less than 1%

b. between 10% and 5%

c. between 5% and 2.5%

d. more than 95%

I think it is A

10. The appropriate conclusion is:

a. Reject the null hypothesis

b. Do not reject the null hypothesis

c. Reject the alternative hypothesis

d. Do not reject the alternative hypothesis

I think it is D