He what is the equation of this graphed line?

Line through (a,b) and (c,d) is

(c-a)(y-b)=(d-b)(x-a)

Line through (0,7) and (8,-2)

(8 - 0)(y - 7) = (-2 - 7)(x - 0)

8(y - 7) = -9 x

y = (-9/8) x + 7

y = (-9/8) x + 7

answer: .64

step-by-step explanation

set up the formula for standard deviation for this set of numbers, then simplify