In a Simple Linear Regression Problem, the Following Statistics Are $\sum ( x - \bar { x } ) ( y - \bar { y } )$

In a simple linear regression problem, the following statistics are calculated from a sample of 10 observations: $\sum ( x - \bar { x } ) ( y - \bar { y } )$ = 2250, $S _ { x }$ = 10, $\sum x$ = 50, $\sum y$ = 75 The least squares estimates of the slope and y-intercept are respectively: $\begin{array}{|l|l|}\hline\text { A. } &225 \text { and }-1117.5\\\hline \text { B. } &2.5 \text { and }-5 \text {. } \\\hline \text { C. } &25 \text { and }-117.5 \\\hline \text { D. } &25 \text { and } 117.5\\\hline\end{array}$