Data Analysis with Microsoft Excel: Updated for Office 2007

Chapter 6 Statistical Inference 241

CONCEPT TUTORIALS

The t Distribution

To see how the t distribution differs from the standard normal, open the

Distributions workbook.

To explore the t distribution:

1 Open the Distributions workbook, located in the Explore folder.

2 Click t from the Table of Contents column. Review the material and

scroll to the bottom of the worksheet.

3 Click the Spin Arrow buttons located next to the Degrees of free-

dom box to change the degrees of freedom for the t distribution.

See Figure 6-10.

Figure 6-10
The
t distribution

as the degrees of freedom increase, the t distribution more

closely approximates the normal distribution

The workbook opens, displaying the t distribution with 1 degree of freedom.

Notice that the t distribution has heavier tails than the superimposed standard

normal distribution. As you increase the degrees of freedom, the t distribution

more closely approximates the standard normal.

Continue exploring the t distribution by changing the degrees of freedom

and observing the changing curve. Close the workbook when you’re fin-

ished. You do not have to save your changes.