Exhibit 18.4.The following ratio-to-moving averages for the seasonally adjusted series were found by the decomposition method applied on a time series representing quarterly sales for the last four years: Refer to Exhibit 18.4.What is the seasonal index for the fourth quarter?
A)1.3300
B)1.3571
C)1.3842
D)1.2942

Question

Exhibit 18.4.The following ratio-to-moving averages for the seasonally adjusted series were found by the decomposition method applied on a time series representing quarterly sales for the last four years:  Refer to Exhibit 18.4.What is the seasonal index for the fourth quarter?
A)1.3300 
B)1.3571 
C)1.3842 
D)1.2942

Quizplus · Accepted Answer

The ratio-to-moving averages for the fourth quarter is 1.3571 (12.89÷9.50). Since the seasonal index is the average of the ratios for a given season, the seasonal index for the fourth quarter is (1.4749 + 1.3646 + 1.3333 + 1.3571) ÷ 4 = 1.3571.