# Sample Size, Margin of error

I) Find the minimum sample size you should use to assure that your estimate of p will be within the required margin of error around the population p.

1) margin of error:0.01; confidence level:95%; from a prior study p is estimated by the decimal equivalent of 55%.

2) Margin of error: 0.007; confidence level: 98%; p and q unknown

II) Find the margin of error : 95% confidence level interval; n =91; x (sample mean)= 85, s= 3.7

#### Solution Summary

Calculates sample size and margin of error given confidence interval.