Negative, because Correlation and slope have the same direction (Sxy will be negative)
1379.52 is the answer to your question
let us take any two points here (5,20) and (7,30)
now let us use slope formula to get its slope
slope =5
now let us use one coordinate (say (5,20)) and slope to get the y intercept
20= 5*5 +b
b=-5
plugging the values of b and m in the given equation we get
y=5x-5
or c=5m-5
I believe 23064 would be his total earnings of last year.