Select the Quick tab of the
1
Sample t-Test: Sample Size Parameters dialog box to access options
to establish the basic parameters for analyzing sample size for the one
sample t-test.

Fixed Parameters. The entries in the boxes under Fixed Parameters establish the fixed, or baseline, parameters for subsequent power 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.

Mu0. In the Mu0 box, enter a value to use for the null hypothesized mean in the t-statistic.

Mu. In the Mu box, enter the value of the actual population mean for the population from which you have sampled.

Alpha. In the Alpha box, enter the type I error rate used in determining the critical value for the t-statistic.

Sigma. In the Sigma box, enter the population standard deviation for the sampled population in the analysis.

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 is greater than or equal to this value.

Type of Hypothesis. Select the appropriate option buttons under Type of Hypothesis to determine the type of null hypothesis tested by the t-statistic.

2-tailed (Mu = Mu0). Select the 2-tailed (Mu = Mu0) option button to use null and alternative hypotheses of the form

H0: m = μ0 H1: m ¹ m0

1-tailed (Mu <= Mu0). Select the 1-tailed (Mu <= Mu0) option button to use null and alternative hypotheses of the form

H0: m ≤ m0 H1: m > m0

1-tailed (Mu >= Mu0). Select the 1-tailed (Mu >= Mu0) option button to use null and alternative hypotheses of the form

H0: m ³ m0 H1: m < m0