The chi-square distribution for developing a confidence interval for a standard deviation has degrees of freedom equal to:
A) n + 2
B) n +1
C) n
D) n - 1
E) n - 2

Question

Quizplus · Accepted Answer

The chi-square distribution for developing a confidence interval for a standard deviation has degrees of freedom equal to n - 1. This is because the sample standard deviation is based on n-1 degrees of freedom (the sample mean is known and used to estimate one degree of freedom).

The Chi-Square Distribution for Developing a Confidence Interval for a Standard