Question

What is the margin of error for 95% confidence for a sample of size 500 where p = 0.5?

Answer 1

The Margin of Error is calculated according to the formula:

$MOE=z*\frac{\sqrt{p*(1-p)}}{\sqrt{n}}$

z = 1.96 for a confidence level (α) of 95% (you have to choose in a normal table), p = proportion (expressed as a decimal), n = sample size.

Replace:

$MOE=1.96*\frac{\sqrt{0.5*0.5}}{\sqrt{500}}=0.0438$

So the answer is D. 0.0438