Use the following data to answer the questions that follow.

a$.$ If the S&P $500$ goes up by $18\mathrm{.}12$ percent, how much should the stocks of Savoy, Hokie, Alison, and Expo change in value?

b$.$ If the stock market drops by $19\mathrm{.}98$ percent, which one of these stocks should outperform the others? Why?