Select the Quick tab of the Single Proportion: Sample Size Parameters dialog box to access options to establish the basic parameters for analyzing sample size for the Z and Chi-Square tests on a single proportion.

Fixed Parameters. The entries in the boxes under Fixed Parameters establish the fixed, or baseline, parameters for subsequent sample size calculations and graphs. Parameters that are not varied explicitly as the independent (X-axis) variables in a graphical analysis will be set equal to these values.

Pi. In the Pi box, enter the actual population proportion for the population sampled from.

Pi0. In the Pi0 box, enter the null hypothesized proportion used in the Z-statistic (or equivalent Chi-square statistic).

Alpha. In the Alpha box, enter the type I error rate for the overall significance test.

Power Goal. In the Power Goal box, enter the minimum acceptable power, for which a minimum sample size is calculated. If the search for an acceptable sample size is successful, the actual power of the statistical test will be greater than or equal to this value.

Type of Hypothesis. The choice of option buttons under Type of Hypothesis determines the type of null hypothesis tested.

2-tailed (Pi = Pi0). Select the 2-tailed (Pi = Pi0) option button to test null and alternative hypotheses of the form

H0:
π

1-tailed (Pi <= Pi0). Select the 1-tailed (Pi <= Pi0) option button to test null and alternative hypotheses of the form

H0:
π

1-tailed (Pi >= Pi0). Select the 1-tailed (Pi >= Pi0) option button to test null and alternative hypotheses of the form

H0:
π