John Wants to Compare Two Means $\overline { x _ { 1 } } = 22.7 , s _ { 1 } ^ { 2 } = 5.4 , n _ { 1 } = 9$

Multiple Choice

John wants to compare two means. His sample statistics were $\overline { x _ { 1 } } = 22.7 , s _ { 1 } ^ { 2 } = 5.4 , n _ { 1 } = 9$ and $\bar { x } _ { 2 } = 20.5 , s _ { 2 } ^ { 2 } = 3.6 , n _ { 2 } = 9$ . Assuming equal variances, the pooled variance is:

A) 4.5
B) 4.9
C) 5.1
D) 3.8