MINITAB LAB # 1: Introduction to Minitab

1. What is Minitab?

Minitab is a statistical software package that provides a wide range of data analysis and graphics capabilities.

2. Where can I use Minitab?

Minitab for Windows is most easily accessed from the Windows XP machines in Wright Hall 112 or 339. A command version of Minitab is available on ACAD, the university mainframe system.

3. How do I access the computers in Wright Hall?

To access the computers in Wright Hall you must have an account.

Follow these steps for logging into a Windows XP machine in Wright Hall:

    1. Find a computer with a screen that says "Begin Logon: Press Ctrl+Alt+Delete to log on"
    2. Next enter your logon information. Both your username and password are provided by the College of Natural Sciences and will be different from your ACAD account. Logon information is case sensitive! Wait as the computer loads your XP profile.
    3. From this point on Windows XP looks and feels very much like Windows 95, 98 or NT. Note: Be sure to log out when you are finished with your XP session! (Start>Shut Down: Close all programs and log on as a different user)

4. Using Minitab

To access Minitab, from the taskbar choose Start>Programs>Math>Minitab. The Minitab screen will show the session window and the data window. The session window records all of your actions and results while using Minitab. The data is organized like a spreadsheet. The top of the screen features a menubar and below it a toolbar.

5. Opening a Data Worksheet

You may enter your own data, open a previously saved data worksheet, or input data from a number of different data sources. For this lab, we will open a previously saved data worksheet on the floppy disk provided by Professor Ecker.

    1. From the file menu, choose Open Worksheet
    2. Locate the file A:\uni.mtw
    3. After you have opened the file you should have uni.mtw in your data window
    4. Save uni.mtw to your Z drive

6. What is in uni.mtw?

The data in uni.mtw is the scholarship summary data for 15 fall semesters from 1984 to 1998. Further details regarding this data can be found at www.uni.edu/regist/statistics/Fscholar.htm. The data in the columns can be explained as follows:

    1. Year
    2. Average Load for All Students – The mean number of credit hours for all students
    3. Average Load for Freshmen
    4. Average Load for Sophomores
    5. Average Load for Juniors
    6. Average Load for Seniors
    7. Average GPA for All Students – The mean semester Grade Index for all UNI students
    8. Average GPA for Male Students
    9. Average GPA for Female Students
    10. Average GPA for Freshmen
    11. Average GPA for Sophomores
    12. Average GPA for Juniors
    13. Average GPA for Seniors

7. What is the mean average load for all students over these 15 fall semesters?

    1. From the Calc menu, choose Column Statistics
    2. Choose Mean as your statistic
    3. Choose C2 AvLoad(All) as your Input Variable
    4. Press OK
    5. Your results are in the session window

8. Can I view more than one statistic at a time?

Minitab can calculate many different statistics at one time for as many columns as you choose.

    1. From the Stat menu, choose Basic Statistics>Display Descriptive Statistics
    2. Select all the variables by holding either the shift or control key down while clicking
    3. Press OK
    4. A listing of your results will appear in the session window

9. Which set of data is more "spread out": The average GPA for males or the average GPA for females?

Given the statistics shown in the session window, make a conclusion about the spread of these two data sets. Type your answer to this question below the statistics in the session window.

10. Which set of data shows a better pattern: The increase in the GPA for males or females?

    1. From the Graph menu, choose Scatterplot then Simple
    2. For Graph 1, choose AvGPA(M) for your Y variable and Year as your X variable
    3. For Graph 2, choose AvGPA(F) for your Y variable and Year as your X variable
    4. Press OK
    5. Type your answer to this question at the bottom of the session window.

11. How can I organize and print my graphs?

    1. To more easily see your results, from the Window menu choose Project Manager
    2. Highlight both graphs from the Graphs folder
    3. Click the Tile button under the Window menu
    4. To return the window to how it was, from the Window menu select 1 Session and then again from the Window menu select 4 uni.mtw
    5. To print your graphs, go back to the Graphs folder in the Project Manager
    6. Select both graphs
    7. Click the Print Selected Graphs button under the File menu
    8. Make sure you are printing to the local printer and press OK

12. How frequently have certain GPA’s been awarded to freshmen?

    1. From the Graph menu, choose Histogram then Simple
    2. For Graph 1, choose AvGPA(Fr) for your X variable
    3. Press OK
    4. Print this graph

13. How can I show the relationship between the median, quartiles, and outliers of all average GPA’s?

    1. From the Graph menu, choose Boxplot then Multiple Y's Simple
    2. Highlight AvLoad(Fr), AvLoad(So), AvLoad(Jr), AvLoad(Sr)
    3. Press Select
    4. Print the graph
    5. Comment on how the average course load has changed from the freshman to senior year

 14. How can I show the frequency of average loads for seniors without losing my original data?

    1. From the Graph menu, choose Stem and Leaf
    2. Choose AvLoad(Sr) as your variable
    3. Press OK
    4. The left hand column displays the number of observations from either end of the stem and leaf, with the count of observations in the same category as the median in parenthesis

15. How do I print my session window?

    1. Before printing the session window, scroll to the top of the session window and type in your name
    2. From the file menu, choose Print Session Window
    3. Make sure you are printing to the local printer and press OK

16. Log out of the Computer

It is important that you log out of Windows XP. From the taskbar, choose Start>Shut Down>Close all programs and log in as a different user.

17. Handing in your Assignment

You should turn in these items in this order:

    1. Session window with your name at the top
    2. Plot of AvGPA(M) vs. Year
    3. Plot of AvGPA(F) vs. Year
    4. Histogram of Frequency of AvGPA(Fr)
    5. One Graph with 4 Boxplots for AvLoad(Fr), AvLoad(So), AvLoad(Jr), AvLoad(Sr)