Education Technology

Solution 35294: Finding T Distribution Values on the TI-84 Plus Family of Graphing Calculators.

How do I find T distribution values on the TI-84 Plus family of graphing calculators?

tcdf( computes the Student t distribution probability between lowerbound and upperbound for the specified df (degrees of freedom), which must be > 0.

Example: Find the area under a T curve with degrees of freedom 4 for P( 1 = X = 5 ).

1) Press [2nd] [DISTR] 6:tcdf(.
2) Input 1 for the the lower bound and press [ENTER].
3) Input 5 for the upper bound and press [ENTER].
4) Input 4 for the degrees of freedom and press [ENTER].

5) Scroll to Paste and press [ENTER].

Your screen should now read tcdf(1,5,4).

6) Press [ENTER]. 

The answer is .1832052662, or about 18.32%.

Please see the TI-84 Plus Family guidebooks for additional information.