Fit another regression, this time adding age, sex, and race in the model. Interpret the regression coefficients and residual standard deviation. Did the effect of beauty change, how so? 2. Use predict of the fitted model, to predict evaluation scores of various levels of beauty (hint: use the newdata argument; set all other variables at their means; use `beauty = seq(-2,2,.1)). Plot the beauty and eval variables and add the fitted regression line. Compare this plot with previous plot