MINITAB Tutorial - GitHub Pages

1 William Mendenhall V1 - 09/20/2010 6:28 Page 1 MINITAB Windows a MINITAB Data Worksheet Readyfor Statistics and Linear Regression and Analysis and Influence Analysis of of Variance for Factorial Series Forecasting1. MINITAB Windows EnvironmentUpon entering into a MINITAB session, you will see a screen similar to Figure bottom portion of the screen is an empty spreadsheet called a MINITAB worksheet with columns representing variables and rows representing observa-tions (or cases). The very top of the screen is the MINITAB main menu bar, withbuttons for the different functions and procedures available in MINITAB . Onceyou have entered data into the spreadsheet, you can analyze the data by clicking theappropriate menu buttons. The results will appear in the Session 1 Initial screenviewed by MINITAB user1 2012 Pearson Education Mendenhall V1 - 09/20/2010 6:28 Page 22 MINITAB Tutorial2.

2 Creating a MINITAB Data Worksheet Readyfor AnalysisYou can create a MINITAB data file by entering data directly into the 2 shows the length-to-width ratio data for the BONES file analyzed inChapter 1. The variables (columns) can be named by typing in the name of eachvariable in the box below the column access data already saved as a MINITAB file, select File on the main menubar, then Open Worksheet, as shown in Figure 3 In the resulting Open Worksheet dialog box (see Figure 4), select the folder where the data file resides, then selectthe data set ( , CONDO). After clicking Open, the data will appear in , if the data are saved in an external text file, access it by selecting Fileon the menu bar, click Other Files, then select Import Special Text (see Figure 5).The Import Special Text dialog box will appear, as shown in Figure 6. Specify thevariable (column) names, then click OK.

3 On the resulting screen, specify the folderthat contains the external data file, click on the file name, then select Open. TheMINITAB worksheet will reappear with the data from the external text : The variables (columns) can be named by typing in the name of eachvariable in the box under the column Listing DataTo obtain a listing (printout) of your data, click on the Data button on the MINITAB main menu bar, then click on Display Data (see Figure 7). The resulting menu, orFigure 2 Data entered into theMINITAB worksheetFigure 3 Accessing a MINITAB data file 2012 Pearson Education Mendenhall V1 - 09/20/2010 6:28 Page 3 Listing Data3 Figure 4 MINITAB OpenWorksheet dialog boxFigure 5 MINITAB options for accessing anexternal data filedialog box, appears as in Figure 8. Enter the names of the variables you want toprint in the Columns constants and matrices to display box (you can do this bysimply clicking on the variables), then click OK.

4 The printout will be displayed inthe Session window. 2012 Pearson Education Mendenhall V1 - 09/20/2010 6:28 Page 44 MINITAB TutorialFigure 6 Import SpecialText dialog boxFigure 7 MINITAB menuoptions for listing dataFigure 8 Display Datadialog box 2012 Pearson Education Mendenhall V1 - 09/20/2010 6:28 Page 5 Graphing Data54. Graphing DataTo obtain graphical descriptions of your data ( , bar charts, histograms, scatter-plots, etc.), click on the Graph button on the MINITAB menu bar. The resultingmenu list appears as shown in Figure 9. Severalof the options covered in this text are(bar) Chart, (scatter) Plot, Histogram, (normal) Probability Plot, and Stem-and-Leaf(display). Click on the graph of your choice to view the appropriate dialog box. Forexample, the dialog boxes for a histogram and scatterplot are shown, respectively,in Figures 10 and 11.

5 Make the appropriate variable selections and click OK to viewthe 9 MINITAB menuoptions for graphing dataFigure 10 Histogram dialog boxes 2012 Pearson Education Mendenhall V1 - 09/20/2010 6:28 Page 66 MINITAB TutorialFigure 11 Scatterplot dialog boxes5. Descriptive Statistics and CorrelationsTo obtain numerical descriptive measuresfor a quantitative variable ( , mean,standard deviation, etc.), click on the Stat button on the main menu bar, then clickon Display Descriptive Statistics (see Figure 12). The resulting dialog box appearsin Figure the quantitative variables you want to analyze and place them in theVariables box. (As an option, you can create histograms and dot plots for the databy clicking the Graphs button and making the appropriate selections.) Click on OKto view the descriptive statistics obtain Pearson product moment correlations for pairs of quantitative vari-ables, click on the Stat button on the mainmenu bar, then click on Basic Statistics,and then click on Correlation (see Figure 12).

6 The resulting dialog box appearsin Figure 13b. Enter the variables of interest in the Variables box, then click OK toobtain a printout of the 12 MINITAB menu options forDescriptive Statistics 2012 Pearson Education Mendenhall V1 - 09/20/2010 6:28 Page 7 Hypothesis Tests7 Figure 13 Descriptive Statistics and Correlation dialog boxes6. Hypothesis TestsTo conduct tests of hypotheses of population parameters ( , means, variances,proportions), click on the Stat button on the MINITAB menu bar, then click onBasic Statistics. The resulting menu appears as shown in Figure 14. Click on theFigure 14 MINITAB menu options forhypothesis tests of means 2012 Pearson Education Mendenhall V1 - 09/20/2010 6:28 Page 88 MINITAB TutorialFigure 15 One-Samplet-Test for Mean dialog boxestest of interest to view the appropriate dialog box, make the appropriate menuselections, and then click OK to view the results.

7 For example, the dialog boxes for a1-Samplet-test for a population mean are shown in Figure 15. In Figure 15a, specifythe quantitative variable to be tested in the Variables box and the null hypothesisvalue in the Test mean box. To specify the confidence level for a confidence intervalfor the mean and to select the form of the alternative hypothesis, click on Optionsand make the selections as shown in Figure 15b. Click OK to return to the 1-Sampletdialog box (Figure 15a), then click OK again to view the test Simple Linear Regression and MultipleRegressionTo conduct a regression analysis of a general linear model, click on the Stat buttonon the MINITAB menu bar, then click on Regression, and click on Regression again,as shown in Figure 16. The resulting dialog box appears as shown in Figure 16 MINITAB menu options forRegression 2012 Pearson Education Mendenhall V1 - 09/20/2010 6:28 Page 9 Simple Linear Regression and Multiple Regression9 Figure 17 Regressiondialog boxSpecify the quantitative dependent variable in the Response box and theindependent variables in the Predictors box.

8 (Note: If your model includes interactionand/or squared terms, you must create andadd these higher-order variables to theMINITAB worksheet before running a regression analysis. You can do this byclicking the Calc button on the MINITAB main menu and selecting the Calculatoroption.)Optionally, you can get MINITAB to produce prediction intervals for futurevalues of the dependent variable and variance inflation factors by clicking theOptions button and checking the appropriate menu items in the resulting menulist. Residual plots are obtained by clicking the Graphs button and making theappropriate selections on the resulting menu. To return to the main Regressiondialog box from any of these optional screens, click OK. Click OK on the Regressiondialog box to view the linear regression an alternative, you can fit general linear models by clicking on the Stat buttonon the MINITAB main menu bar, then click on Regression, and finally click onGeneral Regression (see Figure 16).

9 The resulting dialog box appears in Figure 18 GeneralRegression dialog box 2012 Pearson Education Mendenhall V1 - 09/20/2010 6:28 Page 1010 MINITAB TutorialSpecify the dependent variable in the Response box and the terms in themodel in the Model box. (Note: MINITAB will automatically create the appropriatenumber of dummy variables for each qualitative variable specified. Also, interactionterms are indicated by placing an asterisk between the variables that are to interact[ , LENGTH WEIGHT]. Similar notation is used for squared terms [ ,LENGTH*LENGTH].) Identify the qualitative independent variables in the modelby placing these variables in the Categorical Predictors obtain parameter estimates for all terms in the model, click the Resultsbutton and make the appropriate save predicted values and residuals,click the Storage button and make the appropriate selections.

10 To produce residualplots, click the Graphs button and make your selections. When all the options youdesire have been checked, click OK on the General Regression dialog box to viewthe multiple regression Stepwise RegressionTo conduct a stepwise regression analysis, click on the Stat button on the main menubar, then click on Regression, and click on Stepwise (see Figure 16). The resultingdialog box appears in Figure 19. Specifythe dependent variable in the Responsebox and the independent variables in the stepwise model in the Predictors box. Asan option, you can select the value of to use in the analysis by clicking on theMethods button and specifying the value. (The default is =.15.) Click OK to viewthe stepwise regression conduct an all-possible-regressions selection analysis, click on the Stat buttonon the main menu bar, then click on Regression, and click on Best Subsets (seeFigure 16).