Answer:
y = -1.3x + 10
Step-by-step explanation:
x_avg = (-2 + -1 + 1 + 2 + 3 + 4)/6 = 1.166666...
y-avg = (21 + 8.6 + 1 + 1 + 5 + 14.3) = 8.48333...
x y x-x_avg y-y_avg (x-x+avg)² (x-x_avg)(y-y_avg)
-2 21 -3.1666 12.51666 10.02777 -39.63611
-1 8.6 -2.1666 0.11666 4.69444 -0.252777
1 1 -0.1666 -7.48333 0.02777 1.247222
2 1 0.83333 -7.48333 0.69444 -6.236111
3 5 1.8333 -3.48333 3.3611111 -6.386111
4 14.3 2.8333 5.81666 8.02777 16.480555
sum of (x-x_avg)(y-y_avg) = -34.858
sum of (x+x_avg)² = 26.8333
slope = [(x-x_avg)(y-y_avg)/[(x+x_avg)²]
slope = -34.858/26.8333
slope = -1.29907
y = mx + b
y_avg = m(x_avg) + b
8.48333 = -1.3(1.1666) + b
b = 9.9989
y = -1.3x + 10
