24. (Asian arithmetic forward.) Consider a claim with payoff H = f(S,..., Sn) = (S + + SN)/N - K. Setting v (u/d) and x = d(q* + vp*) show that N E* H So n E* (S+ + Sn) K = x - K= X = N N n=1 Conclude that the proper forward price is So x N+1 K = N = X - 1 X So xN+1 N X - - X - 1 K. 24. (Asian arithmetic forward.) Consider a claim with payoff H = f(S,..., Sn) = (S + + SN)/N - K. Setting v (u/d) and x = d(q* + vp*) show that N E* H So n E* (S+ + Sn) K = x - K= X = N N n=1 Conclude that the proper forward price is So x N+1 K = N = X - 1 X So xN+1 N X - - X - 1 K