to solve this we must know the linear model. first is solve for the slope of the linear model, y = mx + b
m = (y2 - y1) / (x2 - x1)
m = (230-56)/4-1)
m = 58
next is to solve y intercept b, from y = mx + b, using y = 56 and x = 1
56 = (58)1 +b
b = -2
so the equation is
y = 58x - 2
calculate the number of blades of grass is 3 in².
y = (58)(3) - 2
= 172 blades of grass in 3 in².
