Given the following information, calculate the degrees of freedom that should be used in the pooled-variance t test. s₁² = 4 s₂² = 6
N₁ = 16 n₂ = 25
A) df = 41
B) df = 39
C) df = 16
D) df = 25

Question

Quizplus · Accepted Answer

The pooled-variance t test formula for calculating degrees of freedom is:

df = (s₁²/N₁ + s₂²/n₂)² / [(s₁²/N₁)² / (N₁-1) + (s₂²/n₂)² / (n₂-1)]

Substituting the given values, we get:

df = (4/16 + 6/25)² / [(4/16)² / 15 + (6/25)² / 24]
df = 39.26

The degrees of freedom should always be rounded down to the nearest integer, so the answer is df = 39. Therefore, the best choice is B.

Given the Following Information, Calculate the Degrees of Freedom That