A medical researcher is interested in whether patients' left arms or right arms are longer. If 10 patients participate in this study, how many degrees of freedom should the researcher use when finding the critical value for a t test?
A) 9
B) 10
C) 18
D) 19

Question

Quizplus · Accepted Answer

The degrees of freedom for a paired t-test, which is used when comparing two related samples (like left and right arm lengths of the same patients), is calculated as the number of pairs minus one. In this case, there are 10 pairs (patients), so the degrees of freedom is 10 - 1 = 9.

A Medical Researcher Is Interested in Whether Patients' Left Arms