Suggested languages for you:

Americas

Europe

Q.10

Expert-verified
Found in: Page 482

### The Practice of Statistics for AP

Book edition 4th
Author(s) David Moore,Daren Starnes,Dan Yates
Pages 809 pages
ISBN 9781319113339

# How confident? The figure at top right shows the result of taking $25$ SRSs from a Normal population and constructing a confidence interval for each sample. Which confidence level—$80%,90%,95%$, or $99%$—do you think was used? Explain.

The nearest confidence level is $99%$.

See the step by step solution

## Step 1: Given Information

The result of taking $25$ SRSs:

## Step 2: Explanation

The red lines under the curve represent the sample means that do not contain the true population proportion.

We note that there are $0$ out of the $25$ samples that do not contain the true proportion and thus $25$ out of the $25$ samples contain the true proportion:

$\frac{25}{25}=1=100%$

The nearest confidence level is $99%$ (although $95%$ could also be a possible used confidence level).