Fergie has the choice between investing in a State of New York bond at 6.4 percent and a Surething Incorporated bond at 10 percent. Assuming that both bonds have the same nontax characteristics and that Fergie has a 30 percent marginal tax rate, what interest rate does the State of New York bond need to offer to make Fergie indifferent between investing in the two bonds? Note: Do not round intermediate calculations. Round your answer to 2 decimal places