I have a spreadsheet calculating the average of numerical values in different rows. Each month a new column of data is added and the formula for average has to be changed on each row to reflect the average of the data for the last six columns.

Every time I update the data, have to change the formula on every row.

Can I have one formula cell that can be updated to reflect the average of the last six columns that can in turn be referenced by all the other rows that need to have their formula updated so that this is done automatically. In other words would only have to update the one cell in order for all the other cells to be updated?