It costs $5.00 to mo a rectangular field 40 m long and 25 m wide. How much will it cost to mow a similar field 67.5 m wide at the same rate?

I know I'm supposed to use similar figures and ratios. I get (40 m)(25 m) = 1000 m^2 for $5, so $0.005/m^2. The similar rectangles are 40-by-25 and 67.5-by-x, so using ratios gives me x = 42.1875. The area of the similar field is (67.5 m)(42.1875 m) = 2847.65625 m^2, so the cost is about $14.24. But this is wrong?