I have a set of dates and a value against these. What i want to do is create a forecasted trend lines for the weeks ahead based on an average of the last 3 weeks.
Please see data attached. The dates in red are the dates I want to generate and the value for these will be an average of the last 3 values. So the forecasted scroe for row 18 should be an average of 5.6 + 5.9 + 5.9.