Please help Asap!

4. [3 marks] Newton's theory of gravitation states that the weight of a person z feet above sea level is given by: WOR2 W(@) = (R +x)2' where Wo is the person's weight (in lbs) at sea level (i.e. r = 0) and R is the earth's radius (in feet). (a) Determine the differential dw. (b) Suppose that a person weighing Wo = 200 lbs at sea level is flying in a commercial airplane at 52250 ft above sea level. If the earth's radius is R = 20900 000 ft, use the differential in part (a) to approximate their change in weight. Interpret your result