You paid cash for $1,300 worth of stock a year ago. Today the portfolio is worth $1,888. a. What rate of return did you earn on the investment? (Negotive value should be indicated by a minus sign. Round your answer to 2 decimal places.) Rate of retum b. Now suppose that you bought the same stock but bought it on margin The intial margin requirement was 75%. Recalculate your rate of return, ignoring any interest due. (Negotive value should be indicated by o minus sign. Round your onswer to 2 decimal places.) Rate of return % c. Recaiculate the rates of return for a cash purchase in the event that the stock is worth $925 today. (Negative value should be indicated by o minus sign. Round your answer to 2 decimal places.) Rate of return % d. Recalculate the rates of retum for a margin purchase in the event that the stock is worth $925 today. (Negotive value should be indicated by o minus sign. Round your answer to 2 decimal places.) Rate of return %