Chapter 2

Exercises: 2.85, 2.86

Also: In a 1958 study on the smoking habits of twins, R. A. Fisher classified 53 monozygotic (identical) twins and 18 dizygotic (fraternal) twins as having either alike or not alike smoking habits. His results were as follows:

Test the hypothesis that the rate of “alike” smoking habits is the same among monozygotic twins as it is among dizygotic twins.