Test the Hypothesis That $\mu _ { 1 } > \mu _ { 2 }$

Essay

Test the hypothesis that $\mu _ { 1 } > \mu _ { 2 }$ . Two samples are randomly selected from normal populations. The sample statistics are given below.
$$\begin{array} { l l } \mathrm { n } 1 = 18 & \mathrm { n } _ { 2 } = 13 \\\overline { \mathrm { x } } 1 = 530 & \overline { \mathrm { x } _ { 2 } } = 515 \\\mathrm {~s} 1 = 40 & \mathrm {~s} _ { 2 } = 25\end{array}$$