Answer:
0.0417
Explanation:
Given the following;
p = 0.7, n=121
The sampling distribution of sample proportion will be approximately normal with mean
\mu_{\hat{p}}=p=0.7
and standard deviation
\sigma_{\hat{p}}=\sqrt{\frac{p(1-p)}{n}}=\sqrt{\frac{0.7\cdot 0.2}{121}}=0.0417
Check attachment for the curve diagram.