Welder Plus used to have major contracts to produce the Megatron dual chips. The production of dual chips has been declining for the last three years which has contributed to the challenges of forecasting because Welder Plus has not been able to find replacement chips for its product lines. Below is the demand for the past 12 quarters:

2020	2021	2022
Q1	4800	Q1	3500	Q1	3200
Q2	3500	Q2	2700	Q2	2100
Q3	4300	Q3	3500	Q3	2700
Q4	3000	Q4	2400	Q4	1700

Use regression and seasonal indexes (i.e. decomposition technique with linear regression) to forecast demand for the next four quarters for the year 2023. (10 points)