There are 56 blades of grass in 1 in.^2. there 230 blades of grass 4 in^2 of the same lawn

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.