Final answer:
After considering a 25 percent federal tax on an 8 percent corporate bond interest rate, the after-tax interest earnings are 6 percent. This is higher than the tax-exempt 5.5 percent interest earned by the government bond, making the corporate bond the better investment option.
Step-by-step explanation:
The corporate bond you are considering earns an interest of 8 percent, but as it is subject to a federal tax rate of 25 percent, you need to calculate the after-tax yield to compare it with the tax-exempt government bond. The after-tax interest rate of the corporate bond can be found by subtracting the tax paid from the interest earned. The formula for the after-tax yield is Interest Earned × (1 - Tax Rate).
Thus, the after-tax interest earnings on the corporate bond are 6 percent. Given that the government bond earns 5.5 percent interest tax-exempt, the corporate bond's after-tax earnings are still higher than the government bond's earnings.