The following is a Time Series for salve collected over a four year time period for a company in the retail sector quenter 2018 Quarter 95 91 96 2018 98 99 100 110 2020 108 108 102 130 2021 124 131 128 Required (a) Determine the trend ( 7 Marks) (b) Compute seasonal variations using 1 Additive model il Multiplicative model (6 Marks) (6 Marks) (c) Using the seasonal factors calculated above and the following trend values for 2022 prepare the quarters 1, 23, and 4 of 2022 forecasts (6 marks) using additive and multiplication model. del