Section 6.6.

The command %normplot obtains the normal plot of the variable. For example:

MTB > Retrieve 'C:\ISTAT\CAR.MTW'.

Retrieving worksheet from file: C:\ISTAT\CAR.MTW

MTB > %NormPlot c3

Executing from file: C:\MTBSEW\MACROS\NormPlot.MAC

Macro is running ... please wait

gives the following graph:

If the points go around a straight line, we conclude that the data is coming from a normal distribution. Minitab also does the Anderson-Darling test of normality. The null hypothesis is that the distribution is normal. Since the p-value is 0.117, we accept the null hypothesis.

We also can find the normal plot and do the Shapiro-Wilks test by doing

MTB > %NormPlot c3;

SUBC> SWTest.

Comments to: Miguel A. Arcones