Complete the following steps to specify the data for the sample size for estimation calculation.

- Select a Parameter and then enter a Planning Value. You can obtain planning values from related research, design specifications, pilot studies, subject-matter knowledge, or similar information. The planning value that you use depends on the analysis that you want to perform and the parameter that you want to estimate.
Analysis that you want to perform Parameter that you want to estimate Planning value to use 1-Sample Z, 1-Sample t, Paired t

Mean from a normal distribution

Standard deviation

1 Variance

Standard deviation from a normal distribution

Standard deviation

1 Variance

Variance from a normal distribution

Variance

1 Proportion

Proportion from a binomial distribution

Proportion

1-Sample Poisson Rate

Rate from a Poisson distribution

Rate

1-Sample Poisson Rate

Mean from a Poisson distribution

Mean

###### Note

When you estimate the sample size or margin of error for 1-Sample Z, click the Options button, and then select Assume population standard deviation is known.

- From the drop down list, you can choose to estimate sample sizes or margins or error.
- If you select Estimate sample sizes, enter a value for the margin of error. To assess the effect of different margins of error, enter multiple values. When the margin of error is smaller, usually the sample sizes are larger.
- If you select Estimate margins of error, enter a value for the sample size. To assess the effect of different sample sizes, enter multiple values. When the sample sizes are larger, usually the margins of error are smaller.