Minitab Commands
Determination of t-multiplier
1. Select Calc >> Probability Distributions >> t ...
2. Click the button labeled Inverse cumulative probability. (Ignore the box labeled Noncentrality parameter. That is, leave the default value of 0 as is.)
3. Type the number of degrees of freedom in box labeled Degrees of freedom.
4. Click the button labeled Input constant. In the box, type the cumulative probability for
which you want to find the associated t-value.
5. Select OK. The output will appear in the session window.
To create a basic scatter plot
1. Select Graph >> Plot...
2. Specify your Y variable and your X variable in the box provided.
3. Select OK. A new window containing the scatter plot will appear.
A fitted line plot with confidence and/or prediction bands
1. Select Stat >> Regression >> Fitted line plot ...
2. Specify the response and the predictor.
3. Under Options . . . , select Display confidence bands and select Display prediction
bands. Specify the desired confidence level (95% is the default)
4. Select OK. Select OK. A new window containing the fitted line plot will appear.
A standard regression analysis (prediction interval, LOF test)
1. Select Stat >> Regression >> Regression...
2. In the box labeled Response (Y), select the desired response variable.
3. In the box labeled Predictor (X), select the desired predictor variable.
4. (To get a Lack of Fit test) Under Options..., under Lack of Fit Tests, select the box
labeled Pure error.
5. (To get a confidence or prediction interval) Under Options..., in Prediction intervals for
new observations box, specify the X value for which you want to predict Y .
6. Select OK. The standard regression analysis output will be displayed in the session window.
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Residual plots in Minitab’s regression command
1. Select Stat >> Regression >> Regression ...
2. Specify predictor and response.
3. Under Graphs...
(a) select either Regular or Standardized
(b) select desired types of residual plots (normal plot, versus fits, versus order, versus
predictor variable)
4. Select OK. Select OK. The standard regression output will appear in the session window,
and the residual plots will appear in new windows.
Normal plots (and the Ryan-Joiner correlation test) outside of
Minitab’s regression command
1. Select Stat >> Regression >> Regression ...
2. Specify predictor and response.
3. Under Storage...
(a) select either Regular or Standardized
(b) select OK
4. Once Minitab has stored the residuals in your worksheet, select Stat >> Basic Statistics
>> Normality Test...
(a) Specify the residuals variable (named something like RESI1, RESI2, ...).
(b) Select Ryan-Joiner.
(c) Select OK.
Transforming the data
1. Select Calc >> Calculator ...
2. In box labeled “Store result in variable,” tell Minitab in which column (variable) you want
the transformed data stored.
3. Type (input) the expression for the desired transformation in the box labeled Expression.
(Use the available functions.)
4. Select OK. The data will appear in the column of the worksheet that you specified.
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