A coal mining company models the income derived from the continuous production of coal as a continuous income stream using a function f(t), where f(t) = 250e-0.15, where > 0. The function f(t) is measured in thousands of dollars per year, and t is measured in years. Calculate the total income derived from mining coal in the first three years. Give your answer in thousands of dollars to the nearest thousand dollars. Do not include commas or the dollar symbol in your answer. Provido QUE