YouTube would like to test the hypothesis that the standard deviation for the length of an online video watched by a user is more than 2 minutes. A random sample of 21 people who watched online videos was selected. The sample standard deviation for the length of the video was found to be 2.5 minutes. The degrees of freedom for this hypothesis test would be _______.
A)21
B)20
C)18
D)19

Question

Quizplus · Accepted Answer

The degrees of freedom for a hypothesis test concerning the standard deviation or variance is calculated as the sample size minus one. Therefore, with a sample size of 21, the degrees of freedom would be 21 - 1 = 20.

YouTube Would Like to Test the Hypothesis That the Standard