Question

Osteoporosis is a condition in which people experience decreased bone mass and an increase in the risk of bone fracture. Actonel is a drug that helps combat osteoporosis in postmenopausal women. In clinical trials, 1374 postmenopausal women were randomly divided into experimental and control groups. The subjects in the experimental group were administered 5 mg of Actonel, the subjects in the control group were administered a placebo. The number of women who experienced a bone fracture over the course of 1 year was recorded. Of the 696 women in the experimental group, 27 experienced a fracture during the year. Of the 678 women in the control group, 49 experienced a fracture during the year.

a) What is the point estimate for the difference between the fracture rate for women in the experimental group and control groups?

b) State the null and alternate hypothesis we would use to prove whether the women in the experimental experienced a lower rate of bone fractures than the women in the control group.

c) Calculate the test statistic. Show calculation.

d) Run the test in Minitab. Show output. What is the p-value for the test?

e) From the p-value, can we conclude the women in the experimental group had a lower fracture rate than women in the control group? Use a 1% level of significance to make your conclusion.

f) Using Minitab, obtain a 99% confidence interval for the difference in the fracture rate for the women in this study. Does it agree with the test of hypothesis results? Why or why not?

g) What are the assumptions in using the two-sample proportion test and have we met those conditions?

Answer 1