A study set out to determine whether tetrahydrocannabinol (THC, the psychoactive component of marijuana) affects fertility in male hamsters. Two different experiments were conducted, using different measures of fertility. For each experiment, you will test the hypothesis that fertility differs between control hamsters and those treated with THC. You will use the most powerful test for which the data meet assumptions. You must explicitly test these assumptions and show that they are met. If data can be transformed to meet assumptions, then do so, and show that transformation had this effect.
Experiment 1: THC and testis weight.Thirty-six hamsters were randomly assigned to two treatment groups (18 hamsters in each group). One group was administered THC orally three times a week for five weeks at a dose roughly equivalent in humans to three marijuana cigarettes. The control group was administered sesame oil at the same frequency. At the end of the study each hamster was killed and the weight of its testes was measured. The data are shown below. Your assignment is to test for an effect of THC on testes weight.