Random samples of size 100 are taken from a process (an infinite population) whose population proportion is .2. The mean and standard deviation of the distribution of sample proportions are _____.
A) .2 and .04
B) .2 and .2
C) 20 and .04
D) None of the alternative answers is correct.

Question

Quizplus · Accepted Answer

The mean of the distribution of sample proportions is equal to the population proportion, which is .2. The standard deviation of the distribution of sample proportions is calculated using the formula $\sqrt{\frac{p(1-p)}{n}}$, where $p = .2$ and $n = 100$. This gives $\sqrt{\frac{.2(.8)}{100}} = \sqrt{\frac{.16}{100}} = .04$.

Random Samples of Size 100 Are Taken from a Process