Suppose we have an American put option whose current price on old mutual shares is $320,ܴ௙= 12%p.a. and ߪ = 20%. Calculate the value of the American put option on Mutual Limited stock if X= $280 and...

Suppose we have an American put option whose current price on old mutual shares is $320,ܴ௙= 12%p.a. and ߪ = 20%. Calculate the value of the American put option on Mutual Limited stock if X= $280 and the expiry date is 3 months from today using the RNP approach and three binomial steps.