Scenario $3$

Security $1$: A taxable security that offers a before$-$tax yield of $6\mathrm{.}5$ percent, sold to an investor with a marginal tax rate of $20$ percent.

Security $2$: A tax$-$exempt security with a yield of $6$ percent.

Security $1$

Security $2$

Scenario $4$

Security $1$: A $10-$year Treasury bond.

Security $2$: A $30-$year Treasury bond.

Security $1$

Security $2$