Statistics for Six Sigma Green Belts with Minitab and JMP

Testing for the Difference Between Two Variances

To test for the difference in the variances of the waiting times in Wing A and Wing B illustrated in Figure 7.10 on page 133, open the LUGGAGE.MTW worksheet. Select Stat → Basic Statistics → 2 Variances.

1. In the 2 Variances dialog box (see Figure A7.6), select the Samples in different columns option button. (If the samples are in one column, select the Samples in one column option button and enter the column number for the samples and the groups.) In the First: edit box, enter C1 or ‘Wing A’. In the Second: edit box, enter C2 or ‘Wing B’. (If you have summarized data instead of the actual data, select the Summarized data option button and enter values for the sample size and variance.)

   Figure A7.6. ...