Code for #11, Chap 2

generate logsbp=log(sbp)

generate logbmi=log(bmi)

regress logsbp logbmi if sex==1

predict yhatmen, xb

predict menstd_f, stdf

generate menci_uf = yhatmen + invttail(_N-2,0.025)* menstd_f

generate menci_lf = yhatmen - invttail(_N-2,0.025)* menstd_f

scatter logsbp logbmi if sex==1, msymbol(o) scatter yhatmen logbmi if sex
> ==1, c(l) s(i) scatter menci_uf logbmi, c(l) s(i) scatter menci_lf log
> bmi, c(l) s(i)

regress logsbp logbmi if sex==2

predict yhatwom, xb

predict womstd_f, stdf

display invttail(_N-2,0.025)
1.9604692

generate womci_uf = yhatwom + invttail(_N-2,0.025)* womstd_f

generate womci_lf = yhatwom - invttail(_N-2,0.025)* womstd_f

scatter logsbp logbmi if sex==2, msymbol(o) scatter yhatwom logbmi if sex
> ==2, c(l) s(i) scatter womci_lf logbmi, c(l) s(i) scatter womci_uf logb
> mi, c(l) s(i)