Sample Size: Proportion

When entering the confidence level value, the number should be expressed in a decimal format, such as .95.

A positive value for the margin of error must be entered as a positive decimal number less than 1, such as 0.03.

Enter a value for "Estimate of p" only if such a value is known (otherwise, leave it blank). Enter the positive value between 0 and 1 in decimal form. This value might be known from a prior study or from a reasonable estimate of p.

Enter a value for the population size only if sampling is done without replacement from a finite population with a known size. (The population size is usually unknown, and if no entry is made for the population size, it is assumed that sampling is done with replacement or the population size is infinite or very large.)

Click on the Evaluate button to obtain the results.

To close the window, click on the X at the top of the module window.