Question

9

08 - Time Series & Forcasting Help Save & Exit Submit The quarterly production of pine lumber, in millions of board feet, by Northwest Lumber for 2012 through 2016 is: 9 Year winter Spring Sunner Ta11 6.9 9.3 9.7 15.310.1 12.4 16.8 10.7 13.6 17.1 10.3 2013 11.6 17.5 2015 2016 10.7 9.2 points Print aeferences a. Determine the typical seasonal pattern for the production data using the ratio-to-moving-average method. (Round your answers to 4 decimal places c. Deseasonalize the data and determine the linear trend equation. (Round your answers to 4 decimal places.) < Prev9 of 10 Next >

Answer 1

Answer

Answer a)

Calculation of Seasonal Indexes: Quarter 4 2006 1415 0.890 2007 0.629 1.024 1.512 0.803 2008 | 0.804 | 0.890 | 1.363 | 0.857 2009 0.869 0.986 1.348 0.861 2010 0.729 1.079 mean: 0.758 0.995 1.410 0.853 adjusted: 0.755 0.991 1.404 0.849

Answer b)

10.33 10.29 10.47 10.95 9.14 11.7 12.46 10.9511.799.79 10.89 11.89 14.17 12.51 11.96 12.612.19 13.72 12.1812.12 Using Minitab we can find the trend equation for the above deseasonalized data.

Trend Analysis Plot for Deseasonalized data Linear Trend Model Yr 10.1108 + 0.1423*t 1 Variable Actual 14 Fits Accuracy Measures MAPE 5.88164 MAD 0.67815 MSD 0.83490 13 ー12 10 9 2 4 6810 12 1416 18 20 Index

Part d)

Seasonal Adjusted forecast Estimated forecast Seasonal Index 2011 Estimated forecast Index Y 10.1108+0.1423t 1 21 13.0991 0.755 9.890 2 22 13.2414 0.991 13.122 23 13.3837 1404 18.791 4 24 13.526 0.849 11.484