Help with the following. Case study attached.

Refer to Case Study 5.3, "Exercise Yourself to Sleep." (a) Explain whether the authors can conclude that exercise actually caused improvements in sleep. ' This was a randomized experiment, so a causal conclusion is justied. o This experiment could not have been double-blind, and a causal conclusion is never possible with such experiments. This experiment was double-blind, so there should not be any issues with experimenter effects and a causal conclusion is justied. ' This was not a randomized experiment, so a causal conclusion is not possible. This experiment did not include participants who experienced no sleep complaints, so a causal conclusion is not possible. (b) Draw a picture similar to this one from section 5.1 illustrating the process used in this experiment. 43 volunteers 43 volunteers Assignment to groups Random assignment to groups Sleep problems No sleep problems Sedentary Group 5 Compare exercise Compare sleep @0 43 volunteers 43 volunteers Choose groups Assignment to groups sedentary Group No heart disease A Compare sleep Compare sleep According to the UC Davis Health Journal (NovemberDecember 1997, p. 8), older adults constitute only 12% of the population but receive almost 40% of the sedatives prescribed. The purpose of this randomized experiment was to see if regular exercise could help reduce sleep difculties in older adults. The 43 partici pants were sedentary volunteers between the ages of 50 and 76 with moderate sleep problems but no heart disease. They were randomly assigned either to participate in a moderate communitybased exercise program four times a week for 16 weeks or continue to be sedentary. For ethical reasons, the control group was admitted to the program when the experiment was complete. The results were striking. The exercise group fell asleep an average of 11 minutes faster and slept an average of 42 minutes longer than the control group. Note that this could not be a doubleblind experiment because participants obviously knew whether they were exercising. Because sleep patterns were selfreported, there could have been a tendency to err in reporting, in the direction desired by the experimenters. However, this is an example of a well-designed experiment, given the practical constraints, and, as the authors conclude, it does allow the nding that \"older adults with moderate sleep complaints can improve selfrated sleep quality by initiating a regular, moderate intensity exercise program\" (p. 32)