Question

In determining the sample size necessary to estimate a population proportion, which of the following is NOT needed?

Answer 1

Answer:

a. the mean of the population

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$, and a confidence level of $1-\alpha$, we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$.

The margin of error is:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

To find the sample size necessary we need values of M(maximum margin of error), z(related to the confidence level) and $\pi$, which is an estimate of the true population proportion p.

The mean of the population is not needed.

So the correct answer is:

a. the mean of the population