The current stock price of Alcoa is $70 and the stock does not pay dividends. The instantaneous riskfree rate of return is 6%. The instantaneous standard deviation of Alcoa's stock is 30%. You wish to purchase a call option on this stock with an exercise price of $75 and an expiration date 30 days from now. Based on the Black-Scholes Option Pricing Model, the call option's delta (hedge ratio or N(d ₁)) will be __________.