Formula To Calculate Sample Size. When this formula is. N Population size Z Critical value of the normal distribution at the required confidence level p Sample proportion e Margin of error.
Thus we should determine the confidence intervals so that all the values of the sample lie within that interval range. N 1645 2 05 1 -. Z 1645 p 05 e 004.
Z 2 p 1-p c 2.
If youd like to do the calculation by hand use the following formula. This formula was used to calculate the sample sizes in Tables 2 and 3 and is shown below. Yamane 1967886 provides a simplified formula to calculate sample sizes. This calculator uses the following formula for the sample size n.
