Endocrinology A study was performed to determine the effect of introduc- ing a low-fat diet on hormone levels of 73 postmenopausal women not using exogenous hormones [15]. The data in Table 8.25 were presented for plasma estradiol in log,. (picograms/milliliter). TABLE 8.25 Change in plasma estradiol after adopting a low-fat diet Estradiol log, (pg/ml) Preintervention 0.71 (0.26) Postintervention 0.63 (0.26) Difference (postintervention - preintervention) -0.08 (0.20) Values are mean and so (in parentheses) for log (base 10) of preintervention and postintervention measurements and for their difference. 8.99 What test can be performed to assess the effects of adopting a low-fat diet on mean plasma-estradiol levels? 8.100 Implement the test in Problem 8.99, and report a p-value. 8.101 Provide a 95% Cl for the change in mean log,. (plasma estradiol). 8.102 Suppose a similar study is planned among women who use exogenous hormones. How many participants need to be enrolled if the mean change in log,, (plasma es- tradiol) is -0.08, the standard deviation of change is 0.20, and we want to conduct a two-sided test with an a level of 05 and a power of .80