In this exercise, you will complete the Moonbucks application that you created in Exercise $2$ in Chapter $2.($F$3\mathrm{.}1,$ F$3\mathrm{.}3$F$3\mathrm{.}9,$ A$3\mathrm{.}1$A$3\mathrm{.}3,$ A$3\mathrm{.}7)$