Inactive Tutor answered 07/31/19
For this question, you need to isolate r on one side of the equation. When you are given an equation and asked for the equation for another variable, what you are really being asked to do is solve for it.
P = 2250ert (divide both sides by 2250)
P/2250 = ert (then take the natural log)
ln(P/2250) = rt (finally, divide by t)
r = ln(P/2250)/t