Question 21:

Based on Analysis A, how much variation of estradiol was explained by BMI?

Analysis A . reg Estradl bmi Source SS df MS Number of obs = 211 F (1, 209) E 1.97 Model 1581. 81982 1 1581. 81982 Prob > F = 0. 1616 Residual 167580.264 209 801. 819444 R-squared = 0. 9094 Adj R- squared 0. 0946 Total 169162.084 210 805.533732 Root MSE = 28.316 Estradl Coef. Std. Err. t P>| t| [95% Conf. Interval] bmi -. 5066687 . 3607313 -1. 40 3. 162 -1. 217807 . 2044696 cons 55.92546 9.500538 5.89 0.000 37.19629 74.65462Obesity is very common in American society and is a risk factor for breast cancer in postmenopausal women. One mechanism explaining why obesity is a risk factor is that it may raise estrogen levels in women. In particular, one type of estrogen, serum estradiol, is a strong risk factor for breast cancer. To better assess these relationships, researchers studied a group of 151 African-American and 60 Caucasian premenopausal women. Adiposity was measured using BMI = weight (kg)/height2 (m2). BMI is a measure of overall adiposity. In addition, other breast- cancer risk factors were also assessed among these women, including (1) ethnicity (ETHNIC = 1if African-American, = 0 if Caucasian), (2) age (ENTAGE), (3) parity (NUMCHILD = number of children), (4) age at first birth (AGEFBO), (5) any children (ANYKIDS = 1 if yes, = 0 if no), (6) age at menarche (AGEMNRCH = age when menstrual periods began). Use the attached (estradiol stata output.pdf) Stata code and the associated output to answer the following questions