Power Calculation, One-Variance, Chi-Square test

Power calculation for one-Variance, Chi Square test with option for charts of power vs. degrees of freedom, variance, and alpha level.

General

Element Name Description
Population Variance (Var) Specifies population variance for comparison to sample variance.
Sample Variance (Var0) Variance of the sample being tested.
Degrees of Freedom Sample degrees of freedom.

 If a single sample, use N-1.

 If multiple independent samples, use NTtl-J, where NTtl is the total size of all samples and J is the number of samples/groups (acceptable range 1 to 150000).
Alpha Level Alpha level (Type I error rate for Chi Square statistic) (acceptable range 0.0001 to 0.25).
Hypothesis type Hypothesis type selection:

 Two-tailed (Var=Var0, population variance = sample variance);

 One-tailed (Var<=Var0, population variance <= sample variance);

 One-tailed (Var>=Var0, population variance >= sample variance)
Detail of computed results reported Output level of detail selection:

 Power Calculation produces Power Calculation Spreadsheet;

 Pwr Calc plus Charts option produces, in addition, Power vs. Degrees of Freedom, Power vs. Population Variance, and Power vs. Alpha Level charts.

Chart Parameters

Element Name Description
Number of Steps. (For charts only) Number of individual steps for which to calculate power between the starting and ending parameter values for Power Charts. (Min 4, Max 100).
Starting Degrees of Freedom. (For charts only) Initial degrees of freedom value for calculation of Power vs. Degrees of Freedom chart (acceptable range 1 to 140,000).
Ending Degrees of Freedom. (For charts only) Final degrees of freedom value for calculation of Power vs. Degrees of Freedom chart (acceptable range 5 to 150,000).
Starting Variance. (For charts only) Initial population variance value for calculation of Power vs. Variance chart. (must be > 0).
Ending Variance. (For charts only) Final population variance value for calculation of Power vs. Variance chart. (must be > 0).
Starting Alpha". (For charts only) Initial alpha value for calculation of Power vs. Alpha Level chart (acceptable range 0.0001 to 0.2499).
Ending Alpha. (For charts only) Final alpha value for calculation of Power vs. Alpha Level chart (acceptable range 0.0002 to 0.25).