Find the approx. slope of the regression line through the given 5 points. As x increases from 9 to 45 (a change of +36), y increases from 5 to 25, or 20.
20 5
Thus, the slope of the regression line is approx. m = ------ = -----
36 9
We need to continue, to find the equation of this regression line.
Since the slope is 5/9 and one point on the line is (25,12), the equation of the line is:
y-12 = (5/9)(x-25).
Now let x = 80 and calculate y: y = 12 + (5/9)(55) = 12 = 42.6
When the # of apples is 80, the weight of the apples is approx. 43 lb.
