
Ritaank T. answered 03/15/19
MIT student for SAT prep + math
We cannot scale 5:8 with 300:x directly. Linear measures and Area measures are not proportional.
To illustrate this, consider square with side length 2 and area 4 (2^2 = 4).
If we make the side length 3, the area becomes 9.
We scaled the length by 3/2, and the area scaled by 9/4, which is (3/2)^2.
Area scales by the sqaure of the scale of lengths.
Our linear scale is 8/5. Square this ratio, and set it equal to x/300. Cross multiply and solve.
64/25 = x/300. Solve for x