A coin sold for $262 in 1975 and was sold again in 1985 for $422. 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 V₁ = 262. k=0 (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()= c) Estimate the value of the coin in 2007 (Round to the nearest dollar.) d) What is the doubling time for the value of the coin to the nearest tenth of a year? years (Round to the nearest tenth.)