The spot price of copper is $$\$ 0.60$$ per pound. Suppose that the futures prices (dollars per pound) are as follows:
$$\begin{array}{ll}\hline 3 \text { months } & 0.59 \\6 \text { months } & 0.57 \\9 \text { months } & 0.54 \\12 \text { months } & 0.50 \\\hline\end{array}$$
The volatility of the price of copper is $40 \%$ per annum and the risk-free rate is $6 \%$ per
annum. Use a binomial tree to value an American, call option on copper with an exercise price of $\$ 0.60$ and a time to maturity of 1 year. Divide the life of the option into four 3 -month periods for the purposes of constructing the tree. (Hint: As explained in Section 14.7, the futures price of a variable is its expected future price in a riskneutral world.)