what is the magnitude of the elevator's acceleration?

Question

When you weigh yourself on good old terra firma (solid ground), your wieght is 152 lb. In an elevator your apparent weight is 132 lb.

Answer 1

Your weight on good solid ground: mg = 152 lb = 676N, therefore m = 68.9kg (taken g = 9.81m/s^2)
Your weight in the elevator: ma = 132 lb = 587N, therefore a = 8.52m/s^2.
the elevator's acceleration is:
g - a = 9.81m/s^2 - 8.52m/s^2 = 1.29 m/s^2 (downwards)