The stated interest rate is still the nominal rate. To convert nominal to effective rate, the formula is:
r = (1 + i/n)^n - 1
where n=3 because there are 3 quarters in a year
r = (1 + 0.082/3)^3 - 1 = 0.084262
Then, we use the compounding interest formula. Since only half a year is needed to reach the 10-year anniversary, n = 0.5 years.
F = P(1+ r)^n
F = 18000(1 + 0.084262)^0.5
F = $18,743.02
