attached isuseful data set on Lenovo investor relations website. It includes sal

attached isuseful data set on Lenovo investor relations website. It includes sales for each quarter for the past 6 years. I did some analysis in Excel and the data set has trend and seasonal pattern. I calculated seasonal indexesi need help to deseasonalize the data compute trend and write estimated regression equation. Also please do forecast for the next time periods. Additionallyplease forecast the past sales using the regression and compute forecast accuracy. Next please use alternative approach and forecast sales using regression with dummy variables.