The median price, P, of a home rose from $60 thousand in 1980 to $180 thousand in 2000. Let t be the number of years since 1980. If the housing prices increased exponentially, find an equation of the form P = P(initial)*a^t to represent housing prices. (Round your answer for a to 6 decimal places.)

I know the initial value is 60 (thousand) and I have 180 for P, and 20 for t. I've tried to solve the problem with this information, but I keep getting two different answers, neither of which are right according to WebAssign...

Question

The median price, P, of a home rose from $60 thousand in 1980 to $180 thousand in 2000. Let t be the number of years since 1980. If the housing prices increased exponentially, find an equation of the form P = P(initial)*a^t to represent housing prices. (Round your answer for a to 6 decimal places.)

I know the initial value is 60 (thousand) and I have 180 for P, and 20 for t. I've tried to solve the problem with this information, but I keep getting two different answers, neither of which are right according to WebAssign...