In Testing Whether the Means of Two Normal Populations Are $\bar { X } _ { 1 }$

Multiple Choice

In testing whether the means of two normal populations are equal, summary statistics computed for two independent samples are as follows: n1 = 25, $\bar { X } _ { 1 }$ = 7.30, s1 = 1.05.
N2 = 30, $\bar { X } _ { 2 }$ = 6.80, s2 = 1.20.
Assume that the population variances are equal. Then the standard error of the sampling distribution of the sample mean difference $\bar { X } _ { 1 } - \bar { X } _ { 2 }$ is equal to:

A) 0.3072.
B) 0.0917.
C) 0.3028.
D) 0.0944.