options crt;  ? 1e1
freq a;
smpl 64,79;
in colortv;
print pricetv cumprtv;  ? (b)
msd(corr,cova) pricetv cumprtv;  ? (c)
LP = log(pricetv);
LQ = log(cumprtv);
?graph lp lq;  ? (d)
graph(preview) lq lp;  ? (d) -- graphics version
olsq lp c lq;  ? (g)
?plot @res;  ? (h)
plot(preview) @res;  ? (h) -- graphics version