Need help understanding convertible bond calculations. Please help:

Determining values: Convertible bond Craig's Cake Company has an outstanding issue of 15-year convertible bonds with a $1,000 par value. These bonds are convertible into 80 shares of common stock. They have a 13% annual coupon interest rate, whereas the interest rate on straight bonds of similar risk is 16%.

a. Calculate the straight bond value of this bond.

b. Calculate the conversion (or stock) value of the bond when the market price is $9, $12, $13, $15, and $20 per share of common stock.

c. For each of the common stock prices given in part b, at what price would you expect the bond to sell? Why?