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, 578 $1, 496 $1, 381 $1, 254 February 837 801 819 776 829 817 844 795 March April 819 839 820 May 888 891 897 June 823 814 837 July 797 779 811 August 1, 634 1, 484 1,474 september 1, 174 1, 187 1,096 october 825 799 851 November 852 813 878 December 1, 366 1, 267 1,369 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 Regression analysis d. Evaluate a seasonally adjusted trend forecasting model. What is the MAD? (Round your answers to 4 decimal places.) Absolute $ Sales Month Number Period Trend Index Forecast Error (Millions) 1 ,578 2 837 2 3 829 3 4 819 5 888 5 6 823 7 797 8 1,634 8 1,174 9 10 325 10 852 11 1,366 12 1,496 13 801 14 N 817 15 839 16 5 891 17 814 18 779 19 8 1,484 20 1,107 21 10 799 22 313 23 267 24 1,381 25 26 W N - 819 844 27 320 28 5 897 29 837 30 7 811 31 1,474 32 1,096 33 10 351 34 11 878 35 12 1,369 36 1,254 37 N - 776 38 795 39 MAD=&. What Is the averages monthly trend In book-store sales? (Negative amounts should be Indicated by a minus sign. Round your answer to 4 decimal places.) 0.0730] f-1. What are the monthly Indexes? (Reund your answers to 4 decimal places.) f-2. When are book sales the highest? f-3. When are book sales the lowest? g. Predict book sales for the next @ months. (Round your answers to 4 decimal places.) Hovember