7.2 The following equations were estimated using the data in BWGHT.RAW: 4.66.0044 cigs + .0093 log(faminc) + .016 parity log(bwght) (.22) (.0009) (.0059) +.027 male + .055 white (.010) (.013) n 1,388, R2 .0472 (.006) and log(bwght) = 4.65 .0052 cigs + .0110 log(faminc) + .017 par (.0010) (.0085) (.38) + .034 male + .045 white .0030 motheduc + .0032) (.011) (.015) (.0030) n = 1,191, R2 .0493. CLASSRO The variables are defined as in Example 4.9, but we have added a dummy variable for whether the child is male and a dummy variable indicating whether the child is classified as white. (i) In the first equation, interpret the coefficient on the variable cigs. In par- ticular, what is the effect on birth weight from smoking 10 more cigarettes per day? (ii) How much more is a white child predicted to weigh than a nonwhite child, holding the other factors in the first equation fixed? Is the difference sta- tistically significant? (iii) Comment on the stimated effect and statistical significance of motheduc. (iv) From the given information, why are you unable to compute the F statis- tic for joint significance of motheduc and fatheduc? What would you have to do to compute the F statistic?