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

Multiple Choice

John wants to compare two means. His sample statistics were $\bar { x } _ { 1 } = 22.7 , s _ { 1 } ^ { 2 } = 5.4 , n _ { 1 } = 9$ and $\bar { x } _ { 2 } = 20.5 , s _ { 2 } ^ { 2 } = 3.6 , n _ { 2 } = 9$ . Assuming equal variances, the 95 percent confidence interval for the difference of the population means is approximately:

A) [2.44, 6.19].
B) [1.17, 5.08].
C) [0.08, 4.32].
D) [-0.09, 3.19].