The weighted average method is the basic method of index synthesis. It has two forms, namely the addition rule and the multiplication rule.

The weighted average method is also called the “integrated weighted average method” and the “one-month weighted average method”. Inventory cost, which calculates the weighted average unit cost of inventory, based on which a method of calculating the cost of inventories and the cost of inventory at the end of the month is calculated.

Weighted average unit cost of inventory = (balance inventory cost + purchase inventory cost) / (balance inventory quantity + purchase inventory quantity)

Inventory inventory cost = inventory inventory quantity × inventory weighted average unit cost

Cost of inventories issued in the current period = quantity of inventories issued in the current period × inventory weighted average unit cost

or

= initial inventory cost + current income inventory cost - ending inventory cost

The weighted average method, in the market forecast, is to average the different weights according to the importance of each data during the observation period.

Its characteristic is that the average number obtained has included long-term trend changes.