The one-year futures price on a particular stock-index portfolio is 406, the stock index currently is 400, the one-year risk-free interest rate is 3%, and the year-end dividend that will be paid on a $400 investment in the index portfolio is $5.

a. I have already got this problem solution. -----> Formulate a zero-net-investment arbitrage portfolio and show that you can lock in riskless profits equal to the futures mispricing.

b. I need to solution of this problem.------> Now assume (as is true for small investors) that if you short sell the stocks in the market index, the proceeds of the short sale are kept with the broker, and you do not receive any interest income on the funds. Is there still an arbitrage opportunity (assuming you don't already own the shares in the index)?

c. I need to solution of this problem.------> Given the short-sale rules, what is the no-arbitrage band for the stock-futures price relationship? That is, given a stock index of 400, how high and how low can the futures price be without giving rise to arbitrage opportunities?