Year Month 2016 2017 2018 2019 January 1468 1386 1271 1144 February 727 691 709 666 March 719 707 734 685 April 709 729 710 May 778 781 786 June 713 704 727 July 687 669 701 August 1524 1374 1364 September 1064 997 986 October 715 689 741 November 742 703 768 December 1256 1157 1259 The following data report total, monthly U.S. book-store sales in millions of dollars from January 2016 to March 2019. (Go to https://www.census.gov/retail/index.html#mrts, find "Monthly Retail Trade Report," then select "Time Series/Trend Charts" to find the data for the total U.S. bookstore sales.) Year Month 2016 2017 2018 2019 January $1,468 $1,386 $1,271 $1,144 February 727 691 709 666 March 719 707 734 685 April 709 729 710 May 778 781 787 June 713 704 727 July 687 669 701 August 1,524 1,374 1,364 September 1,064 997 986 October 715 689 741 November 742 703 768 December 1,256 1,157 1,259 Click here for the Excel Data File c. Which forecasting model is appropriate based on the data for the total U.S. bookstore sales? Appropriate model d. Evaluate a seasonally adjusted trend forecasting model. What is the MAD? (Round your answers to 4 decimal places.) $ Sales Month Number Period Trend Index Forecast (Millions) Absolute Error 1 1,468 1 2 727 2 3 719 3 4 709 4 5 778 5 6 713 6 7 687 7 8 1,524 8 9 1,064 9 10 715 10 11 742 11 12 1,256 12 1 1,386 13 2 691 14 3 707 15 4 729 16 5 781 17 6 704 18 7 669 19 8 1,374 20 9 997 21 10 689 22 11 703 23 12 1,157 24 1 1,271 25 2 709 26 3 734 27 4 710 28 5 787 29 6 727 30 7 701 31 8 1,364 32 9 986 33 10 741 34 11 768 35 12 1,259 36 1 1,144 37 2 666 38 3 685 39 MAD= e. What is the average monthly trend in book-store sales? (Negative amounts should be indicated by a minus sign. Round your answer to 4 decimal places.) Average monthly trend in book-store sales million dollars per month f-1. What are the monthly indexes? (Round your answers to 4 decimal places.) Month 1 Index 2 3 4 5 6 7 8 9 10 11 12 f-2. When are book sales the highest? When are book sales the highest f-3. When are book sales the lowest? When are book sales the lowest g. Predict book sales for the next 9 months. (Round your answers to 4 decimal places.) Year Month Forecast Sales 2019 April 2019 May 2019 June 2019 July 2019 August 2019 September 2019 October 2019 November 2019 December h. In your judgment, are the forecasts "good"? What disclaimer would you include with your forecast? Yes, forecasts assume that the future sales will be similar to sales over the previous 39 months. O No, forecasts assume that the future sales will not be similar to sales over the previous 39 months.