Q$14.$ We are in the Black and Scholes world and there is a stock that does not pay dividends

for the next two years. The stock price today is $75.$ A put option with a strike price of

$70$ that matures in two years is traded for $7\mathrm{.}01224.$ The discretely compounded risk$-$free

interest rate is $4\mathrm{.}5\%.$ What is the implied volatility?