Cumulative sum by grouping and rolling values formula??
I have a data set with groups, days and visits on those days. I would like to get a rolling sum of every 3 days, so at day 3 the value would be sum of day 1, 2, 3, but on day 4 the value is the sum of days 2, 3,4. And do this by group. I know I can use the cumulative sum by group, but that returns the sum each day, so day 4, would be the sum of all 4 days, but I would like the first day to dro...
