Figure 20.3 shows CCW's average daily call volume for each quarter of the past three years, and column F of Fig. 20.4 gives the seasonally adjusted call volumes. Management now wonders what these seasonally adjusted call volumes would have been if the company had started using seasonal factors two years ago rather than applying them retrospectively now. (Use hand calculations rather than an Excel template)
(a) Use only the call volumes in Year 1 to determine the seasonal factors for Year 2 (so that the "average" call volume for each quarter is just the actual call volume for that quarter in Year 1).
(b) Use these seasonal factors to determine the seasonally adjusted call volumes for Year 2.
(c) Use the call volumes in Year 1 and 2 to determine the seasonal factors for Year 3.
(d) Use the seasonal factors obtained in part (c) to determine the seasonally adjusted call volumes for Year 3.
