The Two Data Sets Are Dependent $\bar { d }$ To the Nearest Tenth

Multiple Choice

The two data sets are dependent. Find $\bar { d }$ to the nearest tenth.
-A hypothesis test is to be performed to test the equality of two population means. The sample sizes are large and the samples are independent. Give an expression for the population standard deviation of the $\left( \bar { x } _ { 1 } - \bar { x } _ { 2 } \right)$ values in terms of $\mathrm { s } _ { 1 } , \mathrm {~s} _ { 2 } , \mathrm { n } _ { 1 }$ , and $\mathrm { n } _ { 2 }$ .

A) $\sqrt{\frac{s_{1}^{2}}{n_{1}}-\frac{s_{2}^{2}}{n_{2}}}$

B) $\sqrt{\frac{s_{1}^{2}}{n_{1}}+\frac{s_{2}^{2}}{n_{2}}}$

C) $\sqrt{\frac{\mathrm{s}_{1}^{2}}{\mathrm{n}_{1}^{2}}+\frac{\mathrm{s}_{2}^{2}}{\mathrm{n} \frac{2}{2}}}$

D) $\frac{s_{1}^{2}}{n_{1}}+\frac{s_{2}^{2}}{n_{2}}$