The following data report total, monthly U.S. gasoline sales in millions of dollars from January 2020 to December 2021. You can access the data in the Excel Data File link below. (Reference source: https://www.census.gov/retail/index.html/mrts. find "Monthly Retail Trade Report," then select "Time Series/Trend Charts.") Year Month Sales ($ millions) 2020 January $39,696 2020 February 36,963 2020 March 34,261 2020 April 26,810 May 32,045 2020 June 36, 314 2020 July 38, 876 2020 August 38, 730 2020 September 37, 231 2020 October 38, 161 2020 November 34,394 2020 December 36, 635 2021 January 37,214 2021 February 36.295 2021 March 46, 360 2021 April 47,274 2021 May 50, 180 2021 June 51,303 2021 JULy 53, 489 2851 August 53,272 2021 September 52,459 2021 october 55.248 2021 November 52, 738 2021 December 52, 308 Click here for the Excel Data File Required: a. Develop a seasonally adjusted trend forecasting model In Excel and use it to answer the following questions. Note: Round your answers to 2 decimal places. a. Develop a seasonally adjusted trend forecasting model In Excel and use it to answer the following questions. Note: Round your answers to 2 decimal places. b. What are the MAD and MAPE? Note: Round your answers to 2 decimal places. MAD MAPE What are the monthly indexes? Note: Round your answers to 3 decimal places. Month Index W N 11 12 d. Forecast sales for January, February, March, and April of 2022. Note: Round your answers to 4 decimal places. Forecasted Sales Period 25 Sales million Period 26 Sales aillion Period 27 Sales million Period 28 Sales million