A researcher wants to estimate the proportion of people who have a pet. A previous study shows that 40% of individuals have a pet. The researcher want to be accurate within 2 percentage points, what is the minimum sample size necessary?
\(\displaystyle 1.96=\frac{2}{\sigma/n^{1/2}}\)
wouldn't I need to know the standard deviation for this question? Or is there some other way to solve it?
Thanks
\(\displaystyle 1.96=\frac{2}{\sigma/n^{1/2}}\)
wouldn't I need to know the standard deviation for this question? Or is there some other way to solve it?
Thanks