# Exercise 2.143 introduces a study examining the relationship between football playing and hippocampal volume, in (mu mathrm{L}),

## Question:

Exercise 2.143 introduces a study examining the relationship between football playing and hippocampal volume, in \(\mu \mathrm{L}\), in the brain. We use the \(n=25\) participants in the control group to estimate average brain hippocampus volume for all non-football playing people. Use the dotplots in Figure 3.20 to answer the following questions.

**(a)** Two dotplots are shown: one shows the original data and one shows a bootstrap distribution from the data. Which is which?

**(b)** Estimate the sample mean hippocampal volume based on the graphs. Give the correct notation and the value.

**(c)** Use the graphs to roughly estimate the standard error if we use this sample mean to estimate hippocampal volume.

**(d)** Does the standard deviation of the original data appear to be larger or smaller than the standard error?

**(e)** Use the estimated mean and the estimated standard error to find and interpret a rough \(95 \%\) confidence interval for the mean hippocampal volume.

**Data From Exercise 2.143:**

A recent study examined the relationship of football and concussions on hippocampus volume in the brain. The study included three groups with \(n=25\) in each group: heathy controls who had never played football, football players with no history of concussions, and football players with a history of concussions. Figure 2.41 shows side-by-side boxplots for total hippocampus volume, in \(\mu \mathrm{L}\), for the three groups.

**Figure 2.41:**

## Step by Step Answer:

**Related Book For**

## Statistics, Enhanced Unlocking The Power Of Data

**ISBN:** 9781119308843

2nd Edition

**Authors:** Robin H Lock, Patti Frazer Lock, Kari Lock Morgan, Eric F Lock, Dennis F Lock