Chapter 10, Problem 1PS

If you have samples of $n_1=12\text{and}{n}_2=15,$ in performing the pooled-variance t test, how many degrees of freedom do you have?

To determine

Determine the number of degrees of freedom.

Answer to Problem 1PS

The required degrees of freedom are 25.

Explanation of Solution

According to the provided information, there are two samples with $n_1=\text{}\text{12}\text{and}{n}_2=\text{15}$ .

To perform a pooled-variance t-test, the degrees of freedom can be calculated as:

$\begin{array}{c}\text{Degrees of Freedom}\left(df\right)=n_1+n_2-\text{2}\\ \text{=}\text{12}+\text{15}-\text{2}\\ =\text{25}\end{array}$

Therefore, the degrees of freedom are 25.