P = $50,000 million the principal

r = 0.12 or 12% annual rate

m = 4 compounding period per year (compounded quarterly)

i = 0.12/4 = 0.03 interest rate per period

t = 5 years is the time in years

n = t*m = 5*4 = 20 is the total number of compounding periods

A = the future value

The formula for the future value is:

A = P(1 + i)^n

A = 50000(1 + 0.03)^20

........

click here to see the step by step calculation

........

A = $90,305.56

At the end of 5 years the compound amount will be $90,305.56.