# How to Do Probability Distributions on a Ti-84 Plus

by Michael Bryant; Updated September 26, 2017Probability distributions are useful for calculating the probability, or likelihood, that a variable will fall within a given range. Often used in market research studies, it is useful in business to predict sales, scores and other numerical data based off research that is either conducted or gathered at a secondary level. While probability distributions are standardized so that they can be calculated by hand, it is much easier to find them using a graphing calculator, such as the TI-84 Plus.

Open "DISTR" by pressing "2ND" and "VARS" to launch the probability distributions menu.

Select the type of probability distribution you wish to use, most commonly being the normal probability distribution, which can be selected by highlighting "normalpdf(" and pressing "ENTER".

Input your lowest value, then highest value, followed by your mean and standard deviation. Separate each with commas and close it with a parenthesis.

Press enter to solve the equation and find the probability distribution.

#### Tips

Using SPSS to supplement the work done on your TI-84 Plus can enhance your statistical capabilities.

#### Warnings

If you do not enter in a mean or standard deviation, they are automatically inputted as "0" and "1" by default.

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