For four years, Marty Campbell invested $4,500 each year in Harley-Davidson. The stock was selling for $80 in 2014, $68 in 2015, $54 in 2016, and $68 in 2017. a. What is Marty's total investment in Harley-Davidson? Total investment b. After four years, how many shares does Marty own? (Do not round intermediate calculations. Round your answer to 1 decimal place.) Number of shares c. What is the average cost per share of Marty's investment? (Use the rounded number of shares computed in part b. Round your answer to 2 decimal places.)