The following data report total, monthly U.S. gasoline sales in millions of dollars from January 2017 to December 2018. (To find the data, go to the site https://www.census.gov/retail/index.html#mrts, find "Monthly Retail Trade Report," then select "Time Series/Trend Charts.") Year Month Sales ($ millions) 2017 Jan $34, 830 2017 Feb 33, 172 2017 Mar 37, 822 2017 Apr 38 , 173 2017 May 39, 939 2017 Jun 39, 209 2017 Jul 38, 997 2017 Aug 40, 417 2017 Sep 40, 546 2017 Oct 40, 917 2017 Nov 39, 386 2017 Dec 39, 246 2018 Jan 38, 423 2018 Feb 36, 577 2018 Mar 41, 848 2018 Apr 42, 309 2018 May 47, 249 2018 Jun 46, 746 2018 Jul 47 , 191 2018 Aug 48, 033 2018 Sep 44, 785 2018 Oct 47 , 542 2018 Nov 42, 439 2018 Dec 38, 826d. Evaluate a seasonally adjusted trend forecasting model. What is the MAD? (Round your answers to 3 decimal places.) Period Month-Year Month Sales ($ Million) Trend Index Forecast Absolute Error 1 Jan-2017 1 34,830 2 Feb-2017 IN 33, 172 W Mar-2017 3 37,822 4 Apr-2017 4 38, 173 May-2017 5 39,939 Jun-2017 6 39,209 Jul-2017 7 38,997 Aug-2017 8 40,417 CO Sep-2017 9 40,546 10 Oct-2017 10 40,917 11 Nov-2017 11 39,386 12 Dec-2017 12 39,246 13 Jan-2018 1 38,423 14 Feb-2018 2 36,577 15 Mar-2018 3 41,848 16 Apr-2018 4 42,309 17 May-2018 47,249 18 Jun-2018 6 46,746 19 Jul-2018 47, 191 20 Aug-2018 8 48,033 21 Sep-2018 9 44,78521 Sep-2018 9 44,785 22 Oct-2018 10 47,542 23 Nov-2018 11 42,439 24 Dec-2018 12 38,826 MAD= e. What are the monthly indexes? (Round your answers to 3 decimal places.) Month Index 1 2 4 5 6 8 CO 10 119 10 11 12 f. Forecast sales for January, February, March, and April of 2019. (Round your answers to 2 decimal places.) Forecasted Slaes Period 25 Sales million Period 26 Sales million Period 27 Sales million Period 28 Sales million