MAT 160 College Algebra FINAL EXAM Page 3 of 11 5. The weight of a body varies inversely as the square of its distance from the center of the Earth. Note: The radius of the Earth is approx. 4000 miles. (a) (4 points) Find a variation model describing the relationship between w, a per- son's weight, and d, the distance from the center of the Earth. (b) (4 points) How much would a 180-lb person weigh 20 miles above the Earth's surface?