Football and Brain Size Exercise 2.143 on page 102 introduces a study that examines several variables on collegiate football players, including the variable Years, which is number of years playing football, and the variable BrainSize, which is volume of the left hippocampus in the brain measured in $\mu \mathrm{L}$. Figure 2.72 shows a scatterplot of these two variables along with the regression line. For each of the following cases, estimate from the graph the number of years of football, the predicted brain size, the actual brain size, and the residual.

Figure 2.72 Relationship of football experience and brain hippocampus size

(a) The case with 18 years of football experience.

(b) The case with the largest positive residual.

(c) The case with the largest negative residual.

Data From Exercise 2.143:
Football and Brain Size 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.

Transcribed Image Text:

Left Hippocampus Volume 4000 3500 3000 2500 2000 T 6 8 10 12 14 16 18 Years of Football