On January 1, a company issued 9%, 10-year bonds with a face amount of $90 million for $84,392,051 to yield 10%. Interest is paid semiannually. What was interest expense at the effective interest rate on June 30, the first interest date?(Enter your answers in whole dollars. Round percentage answers to 1 decimal place (e.g., 0.0234 should be entered as 2.3).)