## t-Testing

## How are we to test a hypothesis of a sample Mean when the is unknown and the sample size is less than 30?

Enter the t-Distribution.

Properties of the t-Distribution

If a population is essentially normal, then the distribution is:

## This is the equation for the Student t-Distribution, or simply t-Distribution, for all samples of size

nless than 30.To find the Rejection Region, we can use the t-Distribution Table. This table merely requires knowledge of the sample size, which allows us to calculate the Degrees of Freedom, and the Significance Level .

## Degrees of Freedom =

n- 1Example: The Height of UCLA Basketball Players

4:14