8.61 More on Exercise and Stress Exercise 6.243 on page 499 introduces a study showing that exercise appears to offer some resiliency against stress, and Exercise 8.21 on page 597 follows up on this intro- duction. In the study, mice were randomly assigned to live in an enriched environment (EE), a stan- dard environment (SE), or an impoverished envi- ronment (IE) for several weeks. Only the enriched environment provided opportunities for exercise. Half the mice then remained in their home cage (HC) as control groups while half were subjected to stress (SD). The researchers were interested in how resilient the mice were in recovering from the stress. One measure of mouse anxiety is amount of time hiding in a dark conpartment, with mice who are more anxious spending more time in darkness. The amount of time (in seconds) spent in darkness during one trial is recorded for all the mice and the means and the results of the ANOVA analysis are shown. There are eight mice in each of the six groups. Group: IE:HC SE:HC EE:HC IE:SD SE:SD Mean: 192 196 205 392 438 Source DF SS Light 5 481776 Error 42 177835 Total 47 659611 MS F 96355.2 39.0 2469.9 P 0.000 EE:SD 231 (a) Is there a difference between the groups in the mount of time spent in darkness? Between which two groups are we most likely to find a difference in mean time spent in darkness? Between which two groups are we least likely to find a difference? (b) By looking at the six means, where do you think the differences are likely to lie?