1. Quarterly party bookings at Terrace Events been recorded as follows. a) Compute the seasonal quarterly indexes given the regression line: 9 = 3 + 4t YEAR Quarter t 9 Ratio QUARTERS 2019 4 7 Seasonally adjusted time series Heading 1 b) Use the seasonal quarterly index to de-seasonalize the time series. YEAR Quarter Seasonally adjusted time series A c) Use the regression line: y = 3 + 4t and the seasonal quarterly indexes to forecast Terrace Events' party bookings for all quarters of 2021. YEAR Quarter t )7 SQ! Forecast 2021 Page 1 of4