SCHOOL OF LIFE SCIENCES AN INTRODUCTION TO THE STATISTICAL SOFTWARE PACKAGE “MINITAB” (For the undergraduate course) 2 / 33 3 / 33 TUTORIAL 1 4 / 33 An Introduction to Minitab Release 14 for Windows The beauty of Minitab is easy-to-use. Minitab is specially designed for those who have not received any formal training course in programming language. Since Minitab is also flexible and powerful, it becomes more and more popular. During following tutorials, we will show what Minitab can do and how Minitab works. Then, the students try to use Minitab to analyse these biostatistics problems on the textbook. Minitab Release 14 runs under the Windows operating system. Minitab Release 14 Minitab version 14 supports multiple worksheets in one environment, which is known as a project. The project consists of the data, text output, worksheets, graphs and dialog boxes associated with your analyses. When you finish a Minitab session or just want to pause it, the project can be saved in the hard disk easily and safely. If you want to restart the project, you just open your project and all work is restored exactly as the last session before you quit. Project file extensions are .MPJ Questions There are several questions interspersed among the tutorials, which are designed to improve your practice of Minitab and the interpretation of results. Practice makes perfect. TO START MINITAB C:program filesMinitab 14Mtb.exe The main Minitab window contains three sub-windows which you should familiarise yourself with before getting started. Worksheet Window Your data will be contained in a worksheet and displayed in the data window. Session Window The results of your analyses will be displayed in the Session window. Project Manager Window (reduced to an icon). This contains folders that allow you to navigate, view, and manipulate various parts of your project. By right-clicking on either the folders or the folder contents, you can access a variety of menus that allow you to manage Session window output, graphs, worksheets, command language, and related project areas. Across the top of the Minitab window is the menu bar from which we can open menus and dialogue boxes and choose commands for statistical analysis and data manipulation. 5 / 33 BEGINNING A SESSION Reference - Minitab Reference Manual Minitab release 14 can be operated in two ways. (1) You can execute commands by choosing them from pull-down menus and by completing the dialogue boxes. We will concentrate on this method in our tutorials. (2) By typing in commands and subcommands at the MTB prompt in the session window. This method is consistent with older versions of MINITAB that operated through DOS. (Active Session Window Editor Enable Commands) Example One Perhaps the easiest way to learn about Minitab is to see a session. The data we will use concerns a sample of 15 poplar trees. Clones are genetically identical cells descended from the same individual. Researchers have identified a single poplar clone that yields fast-growing, hardy trees. These trees may, in the future, serve as an alternative to conventional fuels as an energy source. Researchers at the Pennsylvania State University planted Poplar Clone 252 on two different sites - one, a rich site by a river, and the other, a dry and sandy site on a ridge. They measured the diameter in centimeters, height in meters, and the dry weight of the wood in kilograms for a sample of three year old trees. They were interested in predicting the weight of a tree from its height and diameter measurements. Diameter (cm) Height (m) Weight (kg) 2.23 3.76 0.17 2.12 3.15 0.15 1.06 1.85 0.02 2.12 3.64 0.16 2.99 4.64 0.37 4.01 5.25 0.73 2.41 4.07 0.22 2.75 4.72 0.30 2.20 4.17 0.19 4.09 5.73 0.78 3.62 5.10 0.60 4.77 5.54 1.11 1.39 2.40 0.04 2.89 4.48 0.32 3.90 4.84 0.07 6 / 33 ENTERING DATA Worksheet 1* The Minitab Worksheet is designed to make data entry and data editing simple and efficient. From here you can View your worksheet at any time. Enter data quickly. Change data values easily through full screen editing. Insert or delete single items or entire rows. The active cell in the Data Window has a dark rectangle round it. Make the cell in column 1 row 1 active by clicking on it. To enter a new value into the active cell, type the value and then press either the Arrow Key, Return or click on another cell. Enter the above Poplar Trees example data into the worksheet now. C1, C2 and C3 are the default names for the columns of the worksheet. We can assign more descriptive names - Diameter, Height and Weight for our present example. To do this let us see how to use Minitabs HELP facility. GETTING HELP To access Help open the Help menu or choose the ? from a dialogue box. Finding Information in Help You can find information in Help by doing one of the following: Click the Contents tab in the navigation pane and browse through the table of contents. Informat