automatic fan and medl

Suppose 16% of the listeners of a radio station listen to it while they are at work.
what is the approximate standard deviation of the sampling distribution of the proportion for samples of size 72?

any form of help is greatly appreciated

Question

automatic fan and medl

Suppose 16% of the listeners of a radio station listen to it while they are at work. 
what is the approximate standard deviation of the sampling distribution of the proportion for samples of size 72?

any form of help is greatly appreciated

kropot72 · Answer

The variance of the sample proportion is found from:
$$\large var(\hat{p})=\frac{p(1-p)}{n}$$