Answer:
Step-by-step explanation:
Otay Mesa Water District Bonds are tax free bonds.
They are giving 4.5% interest and Vandell's after tax return is 4.5%.
So we have to calculate a pre-tax return that would be providing the same after tax-return as of Otay Mesa Water District Bonds. Let's assume this return to be x%
Vandell is in the 25% tax bracket, so Vandell's interest will be taxed at 25%.
So,
x ( 100 % - 25 % ) = 4.5
x = 4.5/0.75
x = 6