Forecasting: Moving averages

It depends on the question. If you are given 3-month periods, then the moving average is the average for a 3-month period. If you are given 4-month periods, then the average is the average for a 4-month period, and so on. The problem is this..... If they are 4-month periods, then there are three of them in a year, and the average corresponds to the middle period of the three. We can compare the actual results for that period with the average. If, however, they are 3-month periods, then there are four of them in a year, and the average corresponds to the the very middle 3 months of the year, which does not correspond to any of the four actual 3-month periods. That is why we then need to take a second average so that we have a figure to compare with the actual results for a particular 3-month period.