The le P12_16.xlsx contains the daily closing prices of American Express stock for an eightweek period. a. Using a span of 3, forecast the price of this stock for the next trading day with the moving average method. Round your answer to the nearest cent, if necessary. 14 | 0 How well does this method with span 3 forecast the known observations in this series? Round your answer to three decimal places, if necessary. Root mean square error: | 8 b. Using a span of 6, forecast the price of this stock for the next trading dayr with the moving average method. Round your answer to the nearest cent, if necessary. 34 | (3 How well does this method with span 6 forecast the known observations in this series? Round your answer to three decimal places, if necessary. Root mean square error: I 6