Problem 4-01 You purchase 100 shares for $70 a share ($7,000), and after a year the price rises to $80. Calculate the percentage return on your investment you bought the stock on margin and the margin requirement was (ignore commissions, dividends, and interest expense): a. 15 percent. Round your answer to one decimal place. b. 60 percent. Round your answer to one decimal place % c. 30 percent. Round your answer to one decimal place