According to a recent survey, 47.9 percent of housing units in a large city are rentals. A sample of 210 housing units will be randomly selected. Which of the following must be true for the sampling distribution of the sample proportion of housing units in the large city that are rentals to be approximately normal?

B) The sample size must be greater than 30

Explanation:

According to the central limit theorem the sample size must be greater than 30 in sampling distributions to state that it is approximately normal.

Therefore, the sample size must be greater than 30 for the sampling distribution of the sample proportion of housing units in the large city that are rentals to be approximately normal.

The values of  210(0.479)  and  210(0.521)  must be at least 10.

Explanation:

To assume normality, the values of np and n(1−p) must both be at least 10.