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

Multiple Choice

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:

A) 225 and ?1117.5.
B) 2.5 and ?5.
C) 25 and ?117.5.
D) 25 and 117.5.