The following equations were estimated using the data in BWGHT.RAW:

And

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 particular, 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 statistically significant?
(iii) Comment on the estimated effect and statistical significance of motheduc.
(iv) From the given information, why are you unable to compute the F statistic for joint significance of motheduc and fatheducl what would you have to do to compute the F statistic?

log(bwght) 4.66-.0044 cigs + .0093 log(famnc) + .016 parity 22) 0009) 0059) +027 male 055 white (.006) (010) C013) n 388. R 0472 log(bwght)-4.65 .0052 cigs +.0110 log( famin 017 parity (38) 0010 (0085) +034 male 045 white 0030 motheduc 0032 fatheduc (.006) .0026) (.011) 015 1 , 191 . R. 0030) n .0493