Test Hypotheses Regarding the Difference of Two Independent Means
-Find $\mu _ { 1 } < \mu _ { 2 }$

Multiple Choice

Test Hypotheses Regarding the Difference of Two Independent Means
-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 $\alpha = 0.05$ .
$$\begin{array} { l l } \mathrm { n } _ { 1 } = 35 & \mathrm { n } _ { 2 } = 42 \\\overline { \mathrm { x } } 1 = 20.04 & \overline { \mathrm { x } } 2 = 22.59 \\\mathrm {~s} _ { 1 } = 2.9 & \mathrm {~s} _ { 2 } = 2.8\end{array}$$

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