problem-7.8
problem-7.8
We have a 2 percent margin of error, or
.02 = z
*
\SE(\phat).
But z
*
= 1.96 and \SE(\phat) =
Ö
{.54*(1
-
.54)}/
Ö
n. Solving gives
> phat = .54; zstar = 1.96 > (zstar * sqrt(phat*(1-phat)) / 0.02)^2 [1] 2386