The tutor gives an example of how to use the TI-83 Plus to get results from the t-distribution.

Let’s imagine the following situation:

• Sample size: 25
• Sample mean: 14.4
• Sample standard deviation: 3.3

Estimate the percent of the population between 10.2 and 12.9.

Solution:

On the TI-83 Plus, key the following:

1. 2nd VARS
2. 5 (to choose tcdf)
3. tcdf(should appear. Its parameters are (lower bound, upper bound, degrees of freedom).
4. Key in (10.2-14.4)÷3.3, (12.9-14.4)÷3.3, 24)
5. Hopefully you receive the answer 0.219 (rounded to three decimal places).
6. Apparently, 21.9% of the population lies between 10.2 and 12.9, under these circumstances.

HTH:)

Source:

Texas Instruments TI-83 Plus manual. Texas Instruments, 1999.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.