Chapter 8, Problem 8.1TI

Suppose we have data from a sample. The sample mean is 15, and the error bound for the mean is 3.2. What is the confidence interval estimate for the population mean?

To determine

To find:

The confidence interval.

Answer to Problem 8.1TI

Confidence interval is $\left[11.8,18.2\right]$.

Explanation of Solution

Given:

Sample mean = 15

Margin of error = 3.2

Calculation:

$\begin{array}{l}ConfidenceInterval=\left[\overline{X}\pm M\arg inOfError\right]\\ ConfidenceInterval=\left[15\pm 3.2\right]\\ ConfidenceInterval=\left[11.8,18.2\right]\end{array}$

Conclusion:

The confidence interval is $\left[11.8,18.2\right]$.