A doll sold for $200 in 1975 and was sold again in 1989 for $479. Assume that the growth in the value V of the collector's item was exponential. a) Find the value k of the exponential growth rate. Assume V = 200 k= 0.062 (Round to the nearest thousandth.) b) Find the exponential growth function in terms of t, where t is the number of years since 1975 V(t)=