Suppose that a (non-dividend-paying) stock is currently selling at a price of $71. One year later, the stock price may go up by 15% (with probability 3/4) or it may go down by 7% (with probability 1/4). The risk-free force of interest per annum is 6.2%. A financial derivative on the stock will mature one year from now, and the payoff at maturity equals the square root of the stock price at that time. By applying the binomial model, calculate the current price of this financial derivative