For four years, Mary Thomas invested $4,650 each year in America Bank stock. The stock was selling for $39 in 2015, for $50 in 2016, for $37 in 2017, and for $60 in 2018. (a) What is Mary's total investment in America Bank? Total investment (b) After four years, how many shares does Mary own? (Round your intermediate calculations and final answer to 1 decimal place.) Total shares (c) What is the average cost per share of Mary's investment? (Round your intermediate calculations and final answer to 2 decimal places.) Average cost per share