The one-proportion procedure is used to determine whether a population proportion differs from a specified reference value or hypothesized proportion.

Minitab's power and sample size capabilities allow you to examine how the following test properties affect each other:

·    power - the probability of being able to detect an effect of a given size

·    sample size - the number of observations in the sample

·    comparison proportion - the proportion you want to compare to the hypothesized proportion

If you provide values (or sets of values) for any two of these properties, Minitab will calculate the associated values for the remaining property.

By default, all calculations are based on an a-level of 0.05. However, you can select any value greater than 0 and less than 1.

A direct-mail firm wants to determine if its mailed advertisements result in a response rate that is different from the national average of 65%. A random sample of 1000 households is chosen to receive advertisements for a new product. A difference of 5% from the national average is considered to be meaningful.