Create the following calculation:
window_avg(sum(Sales), 0, 5)
Hope this helps!
You can use the quick table calculation Moving Average.
Your Excel file is the moving average of the current and previous five, while the formula Tracy provided would be looking at the current and next five.
WINDOW_AVG(SUM([Sales]), -5, 0)
would be the formula to match your Excel file.
attached is an example of the quick table calc.
moving average.twbx.zip 6.0 KB