options crt;  ? 7e2
in nerc;
freq a;
smpl 51,84;
print pelec;  ? (a)
print kwh gnp;
?plot kwh gnp;
plot(preview) kwh gnp;
corr kwh gnp;  set rsq5184 = @corr(2)**2;   ?  @corr(2) = @corr(2,1)
smpl 51,73;
 corr kwh gnp;  set rsq5173 = @corr(2)**2;
smpl 74,84;
 corr kwh gnp;  set rsq7484 = @corr(2)**2;
print rsq5173 rsq7484 rsq5184;  ? (b)
smpl 52,84;
lnp1 = log(pelec/pelec(-1));
lng1 = log(gnp/gnp(-1));
lnk1 = log(kwh/kwh(-1));
smpl 52,73;
 msd(corr) lnp1 lng1 lnk1;
smpl 74,84;
 msd(corr) lnp1 lng1 lnk1;
smpl 52,84;
 corr lnp1 lng1 lnk1;