Question

We want to estimate the percentage of political figures who will make a social media

presence by posting an average of 1,000 posts per year next year. How many accounts
must we include in the sample next year, if we want our proportion estimate to be within
20 percentage points at a 90% level of confidence?

Answer 1

0.0208

Explanation:

Using the formula for calculating margin of error is expressed as;

M = z * √p(1-p)/n

z is the z score at 90 % interval

p is the proportion

n is the sample size

p = 0.2

n = 1000

z = 1.645

M = 1.645 * √0.2(1-0.2)/1000

M = 1.645 * √0.2(0.8)/1000

M = 1.645 * 0.01264

M = 0.0208

Hence the margin of error is 0.0208