Chapter 10.3, Problem 100E

(a)

To determine

To state which inference procedure you would use in the following question.

Answer to Problem 100E

Paired t test for the mean differenceis used.

Explanation of Solution

The researchers wants to study about if there is a convincing evidence of the difference in the average number of cars passing through two different intersection.

When we are using a hypothesis test or confidence interval for the proportion we use z test/interval and when we are using a hypothesis test or confidence interval for the mean we use t test/ interval.

Thus, we have given two samples while we are interested in determining if there is a convincing evidence of the difference in the average number of cars passing through two different intersection.Since we want a test to be conducted. And the two samples are dependent and then we should use a Paired t test for the mean difference.

(b)

To determine

To state which inference procedure you would use in the following question.

Answer to Problem 100E

One-sample z test for a proportionis used.

Explanation of Solution

Researchers wants to study about are more than $75\%$ of the Toyota owners are satisfied with their vehicles or not.

When we are using a hypothesis test or confidence interval for the proportion we use z test/interval and when we are using a hypothesis test or confidence interval for the mean we use t test/ interval.

Thus, we have given one samples while we are interested in determining if the claim that more than $75\%$ of the Toyota owners are satisfied with their vehicles is true or not. So, we will use One-sample z testfor a proportion.

(c)

To determine

To state which inference procedure you would use in the following question.

Answer to Problem 100E

Two-sample z interval for the difference in proportionsis used.

Explanation of Solution

The researcher wants to are male college students are more likely to binge drinks than female college students.

When we are using a hypothesis test or confidence interval for the proportion we use z test/interval and when we are using a hypothesis test or confidence interval for the mean we use t test/ interval.

Thus, we are given two samples while we are interested in the claim that male college students are more likely to binge drinks than female college students. Since two samples contain different subjects and they both are independent then we will use Two-sample z interval for the difference in proportions.

(d)

To determine

To state which inference procedure you would use in the following question.

Answer to Problem 100E

Paired t interval for the difference in meansis used.

Explanation of Solution

A bank wants to find out which of the two incentive plans would more increase the use of credit cards and by how much.

When we are using a hypothesis test or confidence interval for the proportion we use z test/interval and when we are using a hypothesis test or confidence interval for the mean we use t test/ interval.

Thus, we are given two samples while we are interested in determining the difference in the mean amount charged. Since the two samples contain same subjects and they are dependent then we should use Pairedtinterval for the difference in means.