An American call option on a stock has an exercise price of $50 and 150 days to expiration. The current stock price is $52 and a dividend of $3 will be paid in 90 days. The volatility of the stock price is 30% p.a. and the continuously compounded riskless interest rate is 12% p.a. What value does Black's Approximation give for the American call option? Show your workings