Newton's Law of Gravitation can be used to show that if an object weighs w pounds on the surface of the earth, then its weight a
t distance x from the center of the earth is W(x) = (wR^2/x^2 ) for x ? R , where R = 3,960 miles is the radius of the earth. At which altitude would an 130-lb person weigh 129.5 lbs? (Round your answer to two decimal places.)