Student's T Probability Lower Tail

Figure 11

To calculate the area under the Student's T Distribution curve, first enter the degrees of freedom, followed by the t-value. It is a two-number function, so it may be entered as either

an in-line function, or by using Æ.

Example:

What is the lower tail probability associated with a Student’s T distribution with 8 degrees of freedom (df1) with a t-value of -1.86?

Table 12-21

Example of Student’s t (lower tail)

 

 

 

 

 

 

 

 

Keys

 

Display

Description

 

 

 

 

 

 

g]IJ7gSy4

.0499653

Calculates the lower tail

 

 

probability.

or, using Æ:

gÆJ7gSy]I

Returns the same results.

 

 

 

Figure 12

Figure 13

Statistical Calculations 131