I ne--ed dir-ect ans-wers to Qu-est-ions

\fThe file P12_16.X|sx 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. Forecast Lower limit $ Upper limit $