1. The following data were reported in a study performed to compare the frequencies of a particular allele in a sample of subjects with adult-onset diabetes and in sample of nondiabetics:
| Diabetic | Nondiabetic | |
|---|---|---|
| Bb or bb | 12 | 4 |
| BB | 39 | 49 |
Use a goodness-of-fit test to test homogeneity between the two samples.
2. A 1959 study looked at the incidence of nausea among postoperative patients for several drugs and a placebo:
| Placebo | Chlorpromazine | Dimenhydrinate | Pentobarbital (100 mg) | Pentobarbital (150 mg) | |
|---|---|---|---|---|---|
| Nausea | 95 | 52 | 52 | 35 | 37 |
| No nausea | 70 | 100 | 33 | 32 | 48 |
Compare the drugs and the placebo. If you reject the hypothesis of homogeneity, perform a test with just the drugs.
3. Italian researchers took samples of 1225 colon cancer patients, 728 rectal cancer patients, and 4154 patients who were in the same hospitals for unrelated reasons (this is the control sample). Each patient was categorized according to his or her olive oil consumption: low, medium, or high. The results were:
| Colon cancer | Rectal cancer | Controls | |
|---|---|---|---|
| Low | 398 | 250 | 1368 |
| Medium | 397 | 241 | 1377 |
| High | 430 | 237 | 1409 |
Is there evidence that the olive oil consumption differs between the three groups?