\begin{tabular}{|r|r|} \hline Date & Adjusted Close \\ \hline 6Nov17 & 95.59 \\ \hline 7Nov17 & 94.68 \\ \hline 8Nov17 & 94.44 \\ \hline 9Nov17 & 93.07 \\ \hline 10Nov17 & 92.84 \\ \hline 13Nov17 & 93.22 \\ \hline 14Nov17 & 93.08 \\ \hline 15Nov17 & 92.59 \\ \hline 16Nov17 & 92.88 \\ \hline 17Nov17 & 93.01 \\ \hline 20Nov17 & 93.27 \\ \hline 21Nov17 & 93.73 \\ \hline 22Nov17 & 93.14 \\ \hline 24Nov17 & 92.80 \\ \hline 27Nov17 & 92.79 \\ \hline 28Nov17 & 94.59 \\ \hline 29Nov17 & 95.90 \\ \hline 30Nov17 & 97.00 \\ \hline 1 Dec-17 & 97.15 \\ \hline 4 Dec-17 & 97.88 \\ \hline 5 Dec-17 & 98.00 \\ \hline \end{tabular} The file P12_16.xlsx contains the daily closing prices of American Express stock for an eight-week period. a. Use the random walk model to forecast the closing price of this stock on the next trading day. Round your answer to the nearest cent, if necessary. \& b. You can be about 95% certain that the forecast made in part a will be off by no more than how many dollars? Round your answers to the nearest cent, if necessary. \begin{tabular}{|r|r|} \hline 6 Dec-17 & 97.50 \\ \hline 7 Dec-17 & 97.87 \\ \hline 8 Dec-17 & 97.84 \\ \hline 11 Dec-17 & 98.28 \\ \hline 12 Dec-17 & 98.65 \\ \hline 13 Dec-17 & 97.07 \\ \hline 14 Dec-17 & 96.45 \\ \hline 15 Dec-17 & 97.81 \\ \hline 18 Dec-17 & 98.96 \\ \hline 19 Dec-17 & 98.43 \\ \hline 20 Dec-17 & 97.80 \\ \hline 21 Dec-17 & 97.79 \\ \hline 22 Dec-17 & 98.03 \\ \hline 26 Dec-17 & 97.86 \\ \hline 27 Dec-17 & 98.41 \\ \hline 28 Dec-17 & 98.98 \\ \hline 29 Dec-17 & 98.59 \\ \hline 2Jan18 & 98.22 \\ \hline 3Jan18 & 98.83 \\ \hline \end{tabular}