In a study of women and heart disease, the following sample results were obtained: Among 10,239 women with low level of physical activity (less than 200 kcal/wk), there were 101 cases of heart disease. Among 9,877 women with physical activity measured between 200 and 600 kcal/wk, there were 56 cases of heart disease.
A. Construct a 90% confidence interval for the difference between the two proportions.
B. At α = 0.10, is there enough evidence to conclude that physical activity reduces the risk of heart disease?