http://finra-markets.morningstar.com/BondCenter/Screener.jsp answer the questions thank you

1. Explain the difference between yield to maturity (YTM) and yield to call (YTC). 2. Halley Enterprise's bonds currently sell for $975. They have a 7-year maturity, an annual coupon of $90, and a par value of $1,000. What is their yield to maturity? (9.51%) 3. The Henderson Company's bonds currently sell for $1,275. They pay a S120 annual coupon, have a 20-year maturity and a par value of $1,000, but they can be called in 5 years at $1,120. What are their YTM and their YTC, and if the yield curve remained flat, which rate would investors expect to earn? (8.99%, 7.31%