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# A study concluded that the mean number of times

Subject: Mathematics    / Statistics
Question

1). A study concluded that the mean number of times adolescents had engaged in vandalism was9.4 times. We think that the true population average is lower than that. We collected our own sample of 200 adolescents and found that the average was 6.5 with a standard deviation of2.01. Conduct a hypothesis test based on our assumption that the true population mean is less than the study’s findings. Set your alpha level to 0.01.

What is the alternative hypothesis (H1)?

a. H1: µ > 9.4

b. H1: µ < 9.4

c. H1: µ < 6.5

d. H1: µ > 6.5

2). A study concluded that the mean number of times adolescents had engaged in vandalism was 9.4 times. We think that the true population average is lower than that. We collected our own sample of 200 adolescents and found that the average was 6.5 with a standard deviation of 2.01.Conduct a hypothesis test based on our assumption that the true population mean is less than the study’s findings. Set your alpha level to 0.01.

A. -4.15

B. -20.4

C. 31.01

D. -8.35

3). A research study found that on average, people illegally use prescription drugs 5 times a year.We think that the population average is different than this. We talk to 12 people and find an average of 2.14 with a standard deviation of 2.04. Conduct a hypothesis test to see if the population average is different. Use an alpha level of 0.05. What’s your alternative hypothesis?

A. H1: µ ? 2.14

B. H1: µ > 5

C. H1: µ > 2.14

D. H1: µ ? 5

4). A research study found that on average, people illegally use prescription drugs 5 times a year.We think that the population average is different than this. We talk to 12 people and find an average of 4 with a standard deviation of 3. Conduct a hypothesis test to see if the population average is different. Use an alpha level of 0.05.

Will you reject or fail to reject the null hypothesis?

a. Reject the null hypothesis

b. Fail to reject the null hypothesis

5). A research study found that on average, people illegally use prescription drugs 5 times a year.We think that the population average is different than this. We talk to12 people and find an average of 2.14 with a standard deviation of 2.04. Conduct a hypothesis test to see if the population average is different. Use an alpha level of 0.05. What is the critical value you’ll use to decide if you reject or fail to reject the null hypothesis?

A. 2.673

B. 1.593

C. 2.201

D. 2.324

6). Say that instead of n = 12, we now have talked to 85 people. So, “A research study found that on average, people illegally use prescription drugs 5 times a year. We think that the population average is different than this. We talk to 85 people and find an average of 4 with a standard deviation of 3. Conduct a hypothesis test to see if the population average is different. Use an alpha level of 0.05.” Would your decision to reject or fail to reject change?

What would it be?

A. Reject the null hypothesis with a new n (n = 85)

B. Fail to reject the null hypothesis with the new n (n = 85)