To find the final amount, we just need to use those values in the compound interest formula, which is
Where A represents the final amount, P the principal(starting value), r the rate(written in decimals), n the number of times the interest is compounded, and t is the time.
We have
P = 20,000
r = 4.5% = 0.045
n = 4 (it is compounded quarterly)
t = 10
Evaluating those values in our equation, we have
The accumulated value will be $31287.54.