Minitab - Central Tendency & Variability

The two groups of data from the overall example are given the names "A" and "B". The Minitab Worksheet is available.

Descriptive Statistics

Use the "Display Descriptive Statistics..." command off of the "Stat, Basic Statistics" menu. That is:

That will take you to the following dialog box:

Type the relevant variable(s) in the box (or double click them from the left hand menu). Then click on the "Statistics..." button which will take you to the following dialog box:.

Make sure you have the boxes that are checked above checked and click the OK button twice. The output will look like this:

 Descriptive Statistics: A, B Descriptive Statistics: A, B Variable N  Mean TrMean StDev Variance Minimum A        6 100.0      *  42.5   1810.0    50.0 B        6 100.0      *  32.2   1040.0    50.0 Variable   Q1 Median    Q3 Maximum Range  IQR A        53.8  100.0 146.3   150.0 100.0 92.5 B        80.0  100.0 120.0   150.0 100.0 40.0

There are several noteworthy points:

• Minitab takes the pain out of the calculations.
• The TrMean is the mean excluding the outer 5% of the distribution.
• We will discuss Q1 & Q3 in later sections of the course.