Chapter 8.1, Problem 9E

(a)

To determine

To Explain: the confidence interval.

Explanation of Solution

Given:

95% Confidence interval for the true difference in the mean number of pairs of shoes for boys and girls

(10.9, 26.5)

There is 95 percent confidence that the true mean number of pair of shoes for girls is greater than the true mean number of pairs of shoes for boys.

(b)

To determine

To Explain: that the confidence interval gives convincing evidence of a difference in the true mean number of pairs of shoes for boys and girls at the school.

Explanation of Solution

Given:

95% Confidence interval for the true difference in the mean number of pairs of shoes for boys and girls

(10.9, 26.5)

It is observed that the confidence interval is not having zero, which showing that it is not likely that there is no difference in the mean number of pairs of shoes for girls and boys. It means that there is enough convincing evidence of a difference in the mean number of pairs of shoes for boys and girls at the school