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 [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].
The margin of error is:
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
To find the sample size necessary we need values of M(maximum margin of error), z(related to the confidence level) and [tex]\pi[/tex], 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
