Question: Does hormone replacement therapy (HRT) cause breast cancer? Researchers studied women ages 50 to 79 who used either HRT or a dummy pill over a 5-year period. Of the 8,304 HRT women, 245 cancers were reported, compared with 185 cancers for the 8,304 women who got the dummy pill. Assume that the participants were randomly assigned to two equal groups.

(a) State the hypotheses for a one-tailed test to see if HRT was associated with increased cancer risk.

(b) Obtain a test statistic and p -value. Interpret the results.

(c) Is normality assured?

(d) Is the difference large enough to be important? Explain.

(e) What else would you need to know to assess this research?