In a study designed to examine the effects of adding cats to the typical American diet, individuals were randomly divided into two different groups. Twice a day, the first group substituted oats for other foods containing carbohydrates; the members of the second group did not make any changes to their diet. One outcome of interest is the serum cholesterol level of each individual eight weeks after the start of the study. Explanatory variables that might affect this response include diet group, serum cholesterol level at the start of the study, body mass index, and gender. The estimated coefficients and standard errors from the multiple regression model containing these four explanatory variables are displayed below [2]. Coefcient Variable Standard I-lrmr Diet Group 4.33 Baseline Cholesterol 0.0? Body Mass Index 0.65 Gender