Minitab is not needed for this activity, but you may use it to check some of your calculations.

- Label four columns as
**me**, and the three personal identifiers from the papers you collected from each student. The example below will assume that they are called**A**,**B**, and**C**. - Enter the values for each person into the appropriate column

This is almost easier to do by hand, so use this as a check rather than as the primary method of finding the values.

The original responses are stored in **A**, **B**, and **C**. We're doing to store the squared differences into **AA**, **BB**, and **CC**.

- Choose Calc / Calculator
- Store your results in
**AA** - The expression is
**A-me**

- Store your results in
- Repeat the Calc / Calculator command
with the second person
- Store your results in
**BB** - The expression is
**B-me**

- Store your results in
- Repeat the Calc / Calculator command
with the third person
- Store your results in
**CC** - The expression is
**C-me**

- Store your results in
- Go to Stats / Basic Statistics / Display Descriptive Statistics
- Put
**AA**,**BB**, and**CC**into the variables box - Click on the statistics button.
- Make sure the
**sum**and**sum of squares**options are checked. You can uncheck the others if you want to. - Click OK

- Make sure the
- Click OK

- Put

The sum and the sum of squares should match with your totals at the end of the rows in question 3.

Do this as a check. I want you to find the values asked for by hand as practice for the test.

Minitab does not find the variation for you. Another name for Variation is Sum of Squares, but the Sum of Squares under the Statistics box is the uncorrected sum of squares, which is what you get if you just square the values and add them up, not the value we want which is found by subtracting the mean before squaring the values.

- Choose Stat / Basic Statistics / Display Descriptive Statistics
- Select the four variables
**me**,**A**,**B**, and**C**by either double clicking each one or by highlighting them all and clicking Select. - Click on Statistics
- Make sure the N non-missing, mean, median, variance, and standard deviation are checked
- Optionally turn off the other statistics
- Click OK

- Click OK

Check the sample size, mean, median, variance, and standard deviation with what you calculated by hand.

The variation can be checked by multiplying the variance by the degrees of freedom (df=n-1).