Tetra Inc. has 5% coupon bonds outstanding that have a remaining maturity of 9 years. These bonds pay interest semiannually and have a $1000 face value. Currently, these bonds are selling for $940....

Tetra Inc. has 5% coupon bonds outstanding that have a remaining maturity of 9 years.  These bonds pay interest semiannually and have a $1000 face value.  Currently, these bonds are selling for $940.  Tetra Inc. faces a marginal tax rate of 40%.  Estimate Tetra'spre-tax cost of debt.