One Variance: Sample Size Parameters - Quick Tab

Select the Quick tab of the One Variance: Sample Size Parameters dialog box to access options to establish the basic parameters for analyzing sample size for the one variance chi-square 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 dependent (X-axis) variables in a graphical analysis will be set equal to these values.

Var.  In the Var box, enter the population variance assumed to hold in the population being tested.

Var0

In the Var0 box, enter the null hypothesized variance.

Alpha

In the Alpha box, enter the type I error rate (a) used in determining the critical value for the chi-square statistic.

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

The choice of option buttons under Type of Hypothesis determines the type of null hypothesis tested by the chi-square statistic.

2-tailed (Var = Var0)

Select the 2-tailed (Var = Var0) option button to use a null and alternative  hypotheses of the form

H₀: σ² = σ²₀    H₁: σ² ¹s²₀

1-tailed (Var <= Var0)

Select the 1-tailed (Var <= Var0) option button to use a null and alternative  hypotheses of the form

H₀: σ² ≤ σ²₀    H₁: σ² > σ²₀

1-tailed (Var >= Var0)

Select the 1-tailed (Var >= Var0) option button to use a null and alternative  hypotheses of the form

H₀: σ² ³ s²₀    H₁: σ² < s²₀