One Variance

Power and Sample Size
Graphs - Ratio

  

If you provide the sample size and power, Minitab calculates the ratio you can detect with the test.

Example Output

 

Interpretation

For the lumber data, Minitab displays one power curve that shows the ratios you can detect when the sample size is 50. The points on the curve represent the ratios that can be detected when power is 0.80 and 0.90.