What of these in Microsoft excel should be used to determine the total value of a column containing average monthly sales for a sales department?

To determine the total value of a column containing average monthly sales in Microsoft Excel, you should use the SUM function. This function adds up all the values in the specified range of cells. For example, if your average monthly sales are in column B from rows 1 to 12, you would use the formula =SUM(B1:B12). This will provide you with the total sales for that period.