1. First, open a word processor of your choice from the Software Server item from the apple menu.

2. Next, click on Software Server from the apple menu and click on other applications. Double click on Statistical Software, then double click on Minitab 10.5 Power Macs to open Minitab.

3. Notice that in Minitab, you have a window that contains your data (which looks like a spreadsheet) and a session window which contains the commands you use to manipulate the data.

4. Click on Open Worksheet from the File menu and double click on the file Grades.mtw. The data window will fill with numbers. The first two columns contain SAT scores for 200 students and the third column contains their GPA afte r 3 years at a certain university. We wish to analyze the data.

5. Click on your word processor icon in the application menu (in the upper right hand corner of the screen) to get back into your word processor. At the top of the sheet, type some title, then skip a few lines. In a sentence, write the descriptio n of the grades data set. Then use the application menu again to go back to Minitab.

6. You wish to make a histogram of the verbal and math scores. Click on Histogram from under the Graph menu. The X under Graph variables should be highlighted. Double click on Verbal then on Math from the menu of v ariables on the left. You will get both histograms at once.

Click on Options. The interesting options are Type of Intervals and Definition of Intervals.
Choose Cutpoint under Type of Intervals in order to have the tick marks appear at the endpoints of the intervals.
Under Definition of Intervals, you may choose

  • Automatic if you wish Minitab to choose the histogram classes for you
  • Number of Intervals if you wish to specify the number of histogram classes
  • Midpoint/Cutpoint positions to specify exact positions for midpoint or cutpoint intervals. To specify, use shorthand notation like 5:40/5 to specify intervals from 5 to 40 in increments of 5.
    Experiment with the bin width (ie the size of the SAT classes) to find one which shows the patterns in the data well. Then click on the Verbal histogram and click on Copy Graph from the Edit menu. Return to your word processor, click below the text, then click Paste from Edit. Your histo gram should appear. Type a return and type a paragraph describing the histogram. Discuss center, spread, and shape and explain what they mean in terms of the scores. Skip a couple of lines and return to Minitab and repeat the above steps (including the paragraph) for the Math histogram. Skip a few lines.

    7. Go back to Minitab and create a boxplot of GPA. Click on boxplot from the graph menu. Click on options, click transpose x and y then click OK (this will create a horizontal boxplot rather than a vertical one). Copy the boxplot to your work processed document and describe the boxplot below it.

    8. USA Today will be running a series relating SAT scores to the GPA performance in college.
    Write a letter to the reporter in charge of this series explaining what you have done. In addition,
    include your ideas on material/concepts USA Today c an use in this series. Suggest specific data you think would be useful to include visually, and discuss your suggestions for the visual presentation of this data.