How to solve this confidence interval? Use the confidence interval to find the estimated margin of error. Then find the sample mean. A store manager says a confidence interval of (44.07, 80.97) when estimating the mean price (in dollars) for the population of textbooks.

How to solve this confidence interval? Use the confidence interval to find the estimated margin of error. Then find the sample mean. A store manager says a confidence interval of (44.07, 80.97) when estimating the mean price (in dollars) for the population of textbooks.
You can still ask an expert for help

• Questions are typically answered in as fast as 30 minutes

Solve your problem for the price of one coffee

• Math expert for every subject
• Pay only if we can solve it

crocolylec
Given a confidence interval (44.07, 80.97)
As confidence interval is $\stackrel{―}{x}=±E,\left(\stackrel{―}{x}+E\right)-\left(\stackrel{―}{x}-E\right)=2E$ where $\stackrel{―}{x}$ is mean price of sample of textbooks and E is margin of error.
Thus, $E=\frac{80.97-44.07}{2}=18.45$
Now, $\stackrel{―}{x}-E=44.07$
Hence, $\stackrel{―}{x}=44.07+18.45=65.52$ is mean price of sample textbooks
Answer: $E=18.45$
$\stackrel{―}{x}=62.52$