Problem
Twenty-four different video games showing alcohol use were observed. The duration times of alcohol use (in seconds) were recorded. When using this sample for a t test of the claim that the population mean is greater than $86 \mathrm{sec}$, what does df denote, and what is its value? What does df denote? A. The test statistic B. The sample standard deviation C. The number of degrees of freedom D. The sample size
Solution
Step 1 ：The df in a t-test usually denotes the degrees of freedom. The degrees of freedom for a sample is typically calculated as the sample size minus 1.
Step 2 ：In this case, since we have 24 different video games, the degrees of freedom would be 24 - 1 = 23.
Step 3 ：Final Answer: The number of degrees of freedom and its value is \(\boxed{23}\).
