This Document Provides An Introduction To The Minitab .

2.2 Saving a project and its partsTo save a project, choose File Save Project As from the menu. Type in afilename in the File name: box and choose a suitable directory to store thefile in and click Save. The first time a file is saved, choosing File SaveProject from the menu (or pressing CTRL S) has the same effect as usingFile Save Project As Once the project has been named, using File SaveProject will automatically overwrite the existing file without requiring entry ofa file name.To save the individual parts of a project choose:TypeInstructionNotesProjectFile SaveProject As Minitab Project (MPJ)WorksheetFile SaveCurrentWorksheet As Available file types are: Minitab worksheet(MTW), Minitab 12, 11, or 10 worksheet(MTW), Portable worksheet (MTP) , Text file(DAT, TXT) , Excel file (XLS), Lotus 1-2-3files (WK?), Quattro Pro file (WB1, WQ1),dBASE/FoxPro file (DBF), Web Page(HTML).SessionWindowFile SaveSession WindowAs Mintab Session (TXT), Rich Text Format(RTF), Web Page (HTML), List File (LIS).GraphFile Save GraphAs The default graph type is MGF (MinitabGraph). Other types are also available:JPEG (Joint Photographic Experts Group),TIFF (Tagged Image File Format), PNG(Portable Network Graphics), BMP(Windows Bitmap). For high qualityprinting, use EPS (encapsulatedpostscript). Note that an EPS file cannot beviewed in a word processor.History fileTXT, MTJNote: It is good practice to save a worksheet as a separate file, so that it willbe stored safely even if the project is corrupted.8

3 Minitab DataIn Minitab, data are contained in a worksheet. This looks similar inappearance to a spreadsheet, but in Minitab cells do not contain formulaethat update results automatically. If a calculated variable is created fromexisting variables, and then the value of one of those variables is updated,the value of the calculated variable will not be updated automatically. AMinitab project may contain several worksheets. Rows in the worksheetrepresent cases. Columns represent attributes of the cases and are knownas variables. Quantitative variables are measured on an ordinal, interval, orratio scale; for example, measuring heights and weights. Qualitative(categorical) variables are measured on a nominal scale; for example genderor machine number. During an experiment, “independent variables” orfactors are set by the experimenter; while “dependent variables” are observedand measured.There are three types of data: Numericnumbers Texttext, numbers, spaces or special characters Date / Timedates e.g.1/1/04, times e.g. 10:20:30AM or bothNote: Although dates can be formatted in a variety of ways, Minitab storesthem internally as numbers and so they can be used in calculations.Data can take three forms: Column Constant MatrixColumns may consist of numbers, text or date / time data. A column can bereferred to either by the letter C followed by a number, e.g. C1 or by avariable name.Constants may contain a single number or a text string e.g. “Paris”. Aconstant can be referred to either by the letter K followed by a number, e.g.K22, or by a variable name.Matrices contain a rectangular block of numbers, and may be referred toeither by the letter M followed by a number, or by a variable name.The following restrictions apply to variable names:9 The length may not exceed 31 characters They must not begin or end with a blank They must not include the symbol ' or # They may not begin with, or consist entirely of, the symbol * They must not be repeated: the same name cannot be used for twovariables (columns, stored constants or matrices) in the sameworksheet

3.1 Working with DataThree windows can be used to work with data: the Data window, theWorksheet folder and the Session window.The Data Window contains columns of data that are in the worksheet. Ifmultiple worksheets are open, each has its own data window, where the datacan be viewed, edited or manipulated.Figure 6The Data WindowThe Worksheet Folder in the Project Manager summarises the columns,stored constants and matrices in the current worksheet.Figure 710The Worksheet Folder

The Session Window can be used to display the columns, constants andmatrices. The command Data Display Data will open a dialog box.Figure 8Display Data Dialog BoxIn Figure 8, the columns id and gender have been selected. (To select avariable, click on its name in the left hand column and then click the Selectbutton.)Clicking on OK in the Display Data dialog box will cause the variable valuesto be displayed in the session window.Figure 9Session Window showing id and gender VariablesNote: If the MTB prompt is on, typing the command Print ‘id’, ‘gender’ in thesession window will achieve this result.11

3.2 Missing ValuesIn circumstances where information about a variable has not been collectedfor any reason, the data item is said to be a missing value. The code for thisis * if the item is numeric, and a blank field if it is alphanumeric (text).Most commands exclude from analysis all rows with a missing value anddisplay the number of excluded points. When an arithmetic commandoperates on a missing value, Minitab sets the result to *.Note: When * is entered as a value in the Data window it should not beenclosed in quotation marks. However, the * must be enclosed in quotationmarks when it is part of the command line typed at the MTB prompt.Task 1Entering Data in the Data EditorActivity 1.1 Run Minitab by clicking Start Programs Statistics Minitab14.When Minitab opens, the session window and an empty worksheetwill be displayed. If the command prompt MTB is not showing in thesession window, select Editor Enable Commands. If the directionarrow in the session window is pointing downwards, click once on itto change the direction to right. (When the direction arrow pointsdownwards, the effect of pressing the Enter key is to move thecursor down to the cell below the current one. Normally data areentered by case).Figure 10The Direction Arrow Pointing RightActivity 1.2 Enter the values Centre, Order, Arrival, Distance in the rowimmediately under that which contains variable numbers. After eachname is entered, press the TAB key to move to the next column.After the last value, type Ctrl Enter to move to the next row. Enterthe dataset shown below:Figure 1112Sample Input Data

When you have completed this task, the worksheet should resemblethe one shown in Figure 12.Figure 12Completed WorksheetNote that the variable number for Centre has changed to C1-T toshow that it is a text variable, the variable numbers for Order andArrival have changed to C2-D and C3-D respectively to show that theyare date variables, and the variable name C4 is unchanged because itis a numeric variable. Note also that where gaps were left in the data,Minitab has inserted asterisks to indicate missing values.Activity 1.3 The entry for the distance variable in the second case is incorrect, andshould show a value of 309. Correct it by selecting the cell and typingthe value 309.Activity 1.4 Select File Save Current Worksheet As and name it Orders. Click Save . Note that you will select a folder of your own, and so thecontents of the screen that you see may differ from this.Figure 1313Save Worksheet Dialog Box

Activity 1.5 Now the project should be saved. Select File Save Project As andname the project Tutorial. Minitab will append the file extension MPJautomatically. Once the project has been saved in this way, it willonly be necessary to click on the SAVE icon on the standard toolbarin order to save it again.Activity 1.6 It would be useful to calculate a new variable to show delivery times.Select Calc Calculator from the menu and then complete the dialogbox as shown below. First enter the name of the new variableDeliveryTime. Click on the variable Arrival and then click Select. Clickon the minus sign in the calculator. Click on the variable Order andthen click Select. Finally, click OK. (Note that a slightly shorter way ofselecting variable names is to double-click on them.)Figure 14The CalculatorActivity 1.7 In Activities 1.1 1.5, the graphical interface was used to perform avariety of tasks. Because we enabled commands before we began, thecorresponding code that Minitab created in order to execute the taskshas been printed in the session window.Figure 1514Minitab Command Language Statements

Task 2Descriptive StatisticsActivity 2.1 This time an existing file will be used. Click File Open Worksheet,and navigate to the directory in which you saved the data files for thistutorial. Select the file Pulse.MTW. This file will now be displayed inanother data window. It may be necessary to rearrange the windowsin order to view all of its contents. The previous worksheet is stillopen, and by dragging the windows it will be possible to see both.Note that only one of the windows is the active window. The activewindow is the one which has three asterisks after its title.Figure 16Active Worksheet Pulse.MTWActivity 2.2 From the menu, select Stat Basic Statistics Display DescriptiveStatistics.Figure 1715Stat Menu showing Basic Statistics Sub-menu

Activity 2.3 Double-click the variables Height and Weight to select them. Click theStatistics button to display the available statistics and then click OKin both dialog boxes.Figure 18Display Descriptive Statistics Dialog BoxThe results will be displayed in the session window.Figure 19Results of AnalysisActivity 2.4 Scroll upwards in the session window to see the commands that havebeen executed as a result of the menu selections.16

Task 3Recoding VariablesActivity 3.1 The variable Sex is a numeric variable which uses the code 1 for maleand 2 for female. A new variable, Gender will be created by recodingthis variable. Click Data Code and select Numeric to Text from thesub-menu.Figure 20Data MenuActivity 3.2 Complete the next dialog box as shown below. Note that when thisfirst appears, the left hand panel shows a list of variables in thecurrent worksheet. Click OK and the new variable Gender will beadded to the worksheet as C9-T.Figure 2117Numeric to Text Dialog Box

Task 4Creating a HistogramActivity 4.1 A histogram of the variable Height will now be created, with separatepanes for the groups male and female. Select Graph Histogram fromthe menu. Choose the option With Fit and click OK.Figure 22Histogram Dialog BoxActivity 4.2 Double-click the variable Height in the left-hand panel to select it andthen click the Multiple Graphs button.Figure 2318Variable Selection Box for Histogram

Activity 4.3 At the next dialog box, click the By Variables tab, and then doubleclick the variable Gender. (Alternatively click once on Gender and thenclick the Select button.)Figure 24Multiple Graphs Dialog BoxClick OK at both dialog boxes and the histogram will be displayed asa separate graph window.Figure 2519Graph Window

Task 5Editing a GraphActivity 5.1 In order to edit a Minitab graph, it is necessary to double-click thearea or object that is to be modified. Double-click the title of thehistogram to display the Edit Title dialog box, make the modificationsshown below and click OK.Figure 26Edit Title Dialog BoxActivity 5.2 Now double-click the white panel area around the graph to producethe required dialog box, and change the background colour. Click OK.Figure 2720Edit Data Region Dialog Box

Activity 5.3 Double-click on the Normal Distribution line to open the EditDistribution Fit dialog box. Make changes to the colour and thicknessof the line.Double-click the bars to open the Edit Bars dialog box, and makechanges to the pattern and colour of the bars.Activity 5.4 Experiment with editing the other areas of the chart. Other optionsinclude: Edit Footnote, Edit Axis Label, Edit Table, Edit Graph andFigure Regions, Edit Bars, Edit Panels and Edit Scale. An exampleof an edited chart is shown below.Figure 28Edited HistogramActivity 5.5 This chart can now be saved for later use. A variety of graphicsformats is available. If the chart is to be used for a web page, asuitable file format would be JPEG or PNG. Make sure that the chartis selected, or the required option will not be available on the FileMenu. Click File Save Graph As Select the arrow to the right of theFiles of Type box and choose JPEG. If necessary, give the chart adifferent name and then click Save.21

4 PrintingThe contents of any Minitab window can be printed. To print a window,select it by clicking on it or selecting it from the Windows menu. An optionto print that window will now be available under the File menu. Forexample, to print a worksheet:Select the appropriate data window and choose File Print Worksheet (orCTRL P). Choose the options required to format the printed output and clickon OK. The standard Windows Print dialog box is displayed. Ensure that thecorrect printer has been selected in the Printer Name box and click OK toprint the window.Depending on the active window, the following options will be available onthe File menu: Print Session Window Print Graph Print Worksheet Print Report Window Print History WindowNote that the session window contains limited formatting. If required, itscontents may be copied and pasted into a Word Processor, where formattingcan be applied.Minitab does have a Report Editor, which allows formatting. Results may becopied from the session window into the Report Editor, formatted, and thenprinted.Task 6Using the Report EditorActivity 6.1 Scroll upwards in the session window until the results of thedescriptive statistics are displayed. Select the output and click Edit Copy. Maximise the Project Manager Window and double-click ReportPad. Click in the right hand panel and select Edit Paste. The resultswill appear in the report, and they can now be edited.Figure 2922Project Manager showing Report Pad open

Activity 6.2 Select the title text and right click the mouse. From the contextsensitive shortcut menu, select Centre. Repeat this process to changethe font size and colour.Figure 30 Shortcut MenuActivity 6.3 Minimise the Project Manager window, and select the chart. Click Edit Copy Graph, and then maximise the Project Manager window. Clickin the report pad window and select Edit Paste. The chart will nowbe displayed.Activity 6.4 With the report pad selected, click File Save Report As Chooseeither RTF (rich text format) or HTML (hypertext markup language),give the file a name and click on Save.Activity 6.5 Select File Print Report Pad.23

Task 7Quitting MinitabYou should always quit any computer program when you have finished yoursession. Never switch off the computer without closing down Windows. Donot leave a computer whilst you are still logged on to it as others may useyour account and could damage your files.Activity 7.1 Before leaving Minitab make sure you have saved the components ofyour work (see Section 2.2). To leave Minitab choose File Exit or clickon the Close box in the top right-hand corner of the Minitab window.If you have made any changes since you last saved your work, you areasked if you want to save changes to your project before closing.Select Yes to save the project, No to exit without saving, or Cancel toreturn to Minitab without savingActivity 7.2 After leaving Minitab, choose Start Logout. You must always logoutbefore leaving your computer.24

Tutorials These step-by-step tutorials introduce the Minitab environment and provide a quick overview of some of Minitab s most important features. Each tutorial is designed to explain the fundamentals of using Minitab, e.g. how to use the menus and dialog boxes, how to man