Question

Ryan invested $4,800 in an account in the year 1990, and the value has been growing exponentially at a constant rate. The value of the account reached $6,300 in the year 1998. Determine the value of the account, to the nearest dollar, in the year 2007.

Answer 1

It grew by a factor of 63/48 in 8 years. So the annual interest rate is
r = (63/48)^(1/12)
Thus the amount after t years is
A = 4800(1+r)^t