In determining monthly seasonal indexes for gas consumption,the sum of the 12 means for gas consumption as a percentage of the moving average is 1150.To get the seasonal indexes,each of the 12 monthly means is to be multiplied by:
A)1150 / 1200
B)(1200 + 1150)/ 12
C)(1150 + 12)/ 1200
D)1200 / 1150

Question

Quizplus · Accepted Answer

To normalize the seasonal indexes so that their sum equals 1200 (100% for each month), each mean percentage (of the moving average) should be adjusted by the factor 1200 / 1150. This ensures that the total of the indexes equals 1200, representing 100% for each of the 12 months.

In Determining Monthly Seasonal Indexes for Gas Consumption,the Sum of the 12