Find the Standardized Test Statistic to Test the Hypothesis That $\mu _ { 1 } < \mu _ { 2 }$

Multiple Choice

Find the standardized test statistic to test the hypothesis that $\mu _ { 1 } < \mu _ { 2 }$ . Two samples are randomly selected from each population. The sample statistics are given below. Use $\alpha = 0.05$ .
$$\begin{array} { l l } \mathrm { n } _ { 1 } = 35 & \mathrm { n } _ { 2 } = 42 \\\overline { \mathrm { x } } 1 = 21.94 & \overline { \mathrm { x } _ { 2 } } = 24.49 \\\mathrm {~s} 1 = 2.9 & \mathrm {~s} _ { 2 } = 2.8\end{array}$$

A) -3.90
B) -3.16
C) -2.63
D) -1.66