Suppose your friend is deciding between investing in two consecutive $1-$year Treasury bonds and a $2-$year Treasury bond. The yield on a $1$year bond is $4\mathrm{.}50\%$ today and the yield on a $2-$year bond is $6\mathrm{.}00\%.$ You tell your friend that if the expected interest rate on a $1-$year bond $1$ year from now is $\_\_\_\_\_\_\_\_\_\_\_\_,$ then she should be indifferent between the two options.