Use the Black-Scholes formula for the following stock:

a. Time to expiration	6 months
b. Standard deviation	52% per year
c. Excercise price	$53
d. Stock price	$53
e. Annual interest rate	2%
f. Dividend	0

Recalculate the value of the call with the following changes:

a.	Time to expiration	3 months
b.	Standard deviation	30% per year
c.	Exercise price	$57
d.	Stock price	$57
e.	Interest rate	4%

Calculate each scenario independently. Please show steps if possible