In determining weekly seasonal indexes for petrol consumption, the sum of the 52 means for petrol consumption as a percentage of the moving average is 5050. To get the seasonal indexes, each weekly mean is to be multiplied by:
A)5200 / 5050.
B)(5200 + 5050) / 52.
C)(5050 + 52) / 5200.
D)5050 / 5200.

Question

Quizplus · Accepted Answer

To find the seasonal indexes, we need to divide the mean for each week by the overall mean (the sum of all 52 means divided by 52). We can express this as:
Seasonal index = Weekly mean / (Sum of all 52 means / 52)

We know that the sum of all 52 means is 5050, so we can substitute this in:
Seasonal index = Weekly mean / (5050 / 52)

Simplifying this expression, we get:
Seasonal index = Weekly mean * (52 / 5050)

Therefore, each weekly mean needs to be multiplied by 52 / 5050 to get the corresponding seasonal index. The only choice that matches this expression is A) 5200 / 5050. We can simplify this expression to get:
52 / 5050 = 4 / 385
So, each weekly mean needs to be multiplied by 4/385 to get the seasonal index for petrol consumption.

In Determining Weekly Seasonal Indexes for Petrol Consumption, the Sum