For four years, Mary Nations invested $4,000 each year in America Bank stock. The stock was selling

Question:

For four years, Mary Nations invested $4,000 each year in America Bank stock. The stock was selling for $34 in 2010, for $48 in 2011, for $37 in 2012, and $52 in 2013.
a. What is Mary's total investment in America Bank?
b. After four years, how many shares does Mary own?
c. What is the average cost per share of Mary's investment?