Pre-Calc Application Problem

Question

If Amy weighs 120 lbs at sea level, how much will she weigh on Pike's Peak, which is 14,110 ft above sea lvl?

If an object weighs m pounds at sea level. then its weight W (in lbs) at height of h miles above sea level is given approximately by the equation

W(h) = m(4000/4000+h)^2 

a) answered, need help with b!

b)At what height will Amy weigh 119.95 lbs

Answer 1

119,95 = 120(4000/4000+h)^2

4000/4000+h = sqr(119.95/120)

4000+h = 4000/sqr(199.95/120)

h= 4000/sqr(199.95/120) -4000

h=4000/.9977-4000

=4009.2-4000

h=9.2 feet above sea level for 119.45 pounds at sea level