Over a four-year period, LaKeisha Thompson purchased shares in the Oakmark Investor Class Fund. Using dollar cost averaging. calculate the number of shares before completing this problem. (Round your answers to the nearest whole number.) a. At the end of four years, what is the total amount invested? b. At the end of four years, what is the total number of shares purchased? (Round your intermediate calculations and final answer to the nearest whole number.) c. At the end of four years, what is the average cost for each share? (Round your intermediate calculations to the nearest whole number. Round final answer to 2 decimal places.)