HELP Use two points to enter an equation for the function. Give your answer in the form a(b)n. In the event that a = 1, give your answer in the form (b)n.

A child starts a playground swing from standing and doesn't use her legs to keep swinging. On the first swing she swings forward by 18 degrees, and on the second swing she only comes 13.5 degrees forward. The measure in degrees of the angle m(n) is an exponential function of the number n of swings.