The article “Increases in Steroid Binding Globulins Induced by Tamoxifen in Patients wit...

The article “Increases in Steroid Binding Globulins Induced by Tamoxifen in Patients with Carcinoma of the Breast” (J. of Endocrinology, 1978: 219–226) reports data on the effects of the drug tamoxifen on change in the level of cortisol- binding globulin (CBG) of patients during treatment. With age= x and Δ CBG = y, summary values are n = 26,

a. Compute a 90% CI for the true correlation coefficient r.

b. Test H0: ρversus at level .05.

c. In a regression analysis of y on x, what proportion of variation in change of cortisol-binding globulin level could be explained by variation in patient age within the sample?

d. If you decide to perform a regression analysis with age as the dependent variable, what proportion of variation in age is explainable by variation in ΔCBG?