Answer:
The balance in Lee's account is $72,680.5
Explanation:
The formula to calculate amount for a compound interest is given as,
A = P(1+r)^n
Since the interest is compounded semiannually, at the end of year 3, the amount in Lee's account would be = 15000(1+0.09)^6 = 15000(1.09)^6 = $25,156.50
At the beginning of year 4, she deposits an additional $40,000
At the end of year 4, the amount in Lee's account would be = 40,000(1+0.09)^2 = 40,000(1.09)^2 = $47,524
Lee's balance = $25,156.50 + $47,524 = $72,680.5