Medical researchers followed 6272 Swedish men for 30 years to see if there was any association between the amount of fish in their diet and prostate cancer. ("Fatty Fish Consumption and Risk of Prostate Cancer", Lancet, June 2001)
|
Fish Consumption
|
Total Subjects
|
Prostate Cancers
|
|
Never/seldom
|
124
|
14
|
|
Small part of diet
|
2621
|
201
|
|
Moderate part
|
2978
|
209
|
|
Large part
|
549
|
42
|
a) Is this a survey, a retrospective study, a prospective study, or an experiment? Explain.
b) Is this a test of homogeneity or independence?
c) Do you see evidence of an association between the amount of fish in a man s diet and his risk of developing prostate cancer?
d) Does this study prove that eating fish does not prevent prostate cancer? Explain.