Chapter 8.1, Problem 14E

(a)

To determine

To Explain: the confidence interval.

Explanation of Solution

Given:

90 percent confidence interval for the median household income in the New Jersey is

  $\$72222\pm \$610$

Calculation:

  $\begin{array}{l}\$72222\pm \$610\\ =\left(\$71612,72832\right)\end{array}$

There is confident that there income in new Jersey is between $71612 and $72832 of the true 2015 median household.

(b)

To determine

To Explain: the confidence level.

Explanation of Solution

The 90 percent confidence interval is showing that the population median household income in New Jersey. It implies that it is expecting about 90 percent of all samples is having a 90 percent confidence interval which is having the true population parameter.