This post explains how to calculate Weighted Average in Excel with percentages. In a standard arithmetic average where the sum of values is divided by the number of values, each data value is treated ...

To do this, with the 1% cell still copied, select the cells containing the values you want to convert from whole numbers into ...

What <B>Manus</B> said, although it'd most likely work better for you if you worked horizontally rather than vertically. A1 would be the sales, B1 would be the division formula, and C1 would subtract ...