TEXTBOOKS&References 1. Business Forecasting by Hanke & Wichern, 8 edition Pearson Printice Hall 2005 Prentice Hall 2005

Q1. The monthly sales levels (measures in thousands of Saudi riyals) for a leading Saudi company are shown in the following table. Plot the monthly sales data using minitab and the demonstrate the following: a) Smooth the data and forecast Jan 2019 sales level using simple exponential smoothing with a smoothing constant of 0.5 and initial smoothed value of 16.8. Plot and show the fits, residuals and forecast in a table. b) Smooth the data and forecast Jan 2019 sales level using Holt's linear smoothing with all smoothing constants equal to 0.5 and initial smoothed value of 16.8. Plot and show the fits, residuals and forecast in a table. c) Smooth the data and forecast Jan 2019 sales level using Winters' multiplicative smoothing with all smoothing constants equal to 0.5 and initial smoothed value of 16.8. Plot and show the fits, residuals and forecast in a table. d) Compare and evaluate the previous exponential smoothing methods in parts (a), (b) and (c) using MAPE, MAD and MSE, and explain your preferred method for these date. Show your comparison in a table. Year Month Sales Year Month Sales Year Month Sales Jan 16.8 Jan 15.3 Jan 27.7 Feb 12.7 Feb 30.8 Feb 36.3 Mar 26.9 Mar 25.5 51.1 Apr 61.4 Apr 103.1 Apr 217.5 May 147.8 May 197.6 May 206.2 2016 Jun 57.9 2017 Jun 68.6 2018 Jun 110.0 Jul 51.3 Jul 39.9 Jul 102.8 Aug 53.5 Aug 91.3 Aug 128.8 Sep 23.0 Sep 58.7 Sep 104.7 Oct 41.3 Oct 59.6 Oct 111.0 Nov 19.3 Nov 33.4 Nov 63.7 Dec 22.7 Dec 53.7 Dec 82.6 Mar Q1. The monthly sales levels (measures in thousands of Saudi riyals) for a leading Saudi company are shown in the following table. Plot the monthly sales data using minitab and the demonstrate the following: a) Smooth the data and forecast Jan 2019 sales level using simple exponential smoothing with a smoothing constant of 0.5 and initial smoothed value of 16.8. Plot and show the fits, residuals and forecast in a table. b) Smooth the data and forecast Jan 2019 sales level using Holt's linear smoothing with all smoothing constants equal to 0.5 and initial smoothed value of 16.8. Plot and show the fits, residuals and forecast in a table. c) Smooth the data and forecast Jan 2019 sales level using Winters' multiplicative smoothing with all smoothing constants equal to 0.5 and initial smoothed value of 16.8. Plot and show the fits, residuals and forecast in a table. d) Compare and evaluate the previous exponential smoothing methods in parts (a), (b) and (c) using MAPE, MAD and MSE, and explain your preferred method for these date. Show your comparison in a table. Year Month Sales Year Month Sales Year Month Sales Jan 16.8 Jan 15.3 Jan 27.7 Feb 12.7 Feb 30.8 Feb 36.3 Mar 26.9 Mar 25.5 51.1 Apr 61.4 Apr 103.1 Apr 217.5 May 147.8 May 197.6 May 206.2 2016 Jun 57.9 2017 Jun 68.6 2018 Jun 110.0 Jul 51.3 Jul 39.9 Jul 102.8 Aug 53.5 Aug 91.3 Aug 128.8 Sep 23.0 Sep 58.7 Sep 104.7 Oct 41.3 Oct 59.6 Oct 111.0 Nov 19.3 Nov 33.4 Nov 63.7 Dec 22.7 Dec 53.7 Dec 82.6 Mar