I'm trying to automatically calculate a new average every week, so I can see the evolution of the average over the past weeks.
I have one column with the week numbers. The second column contains an amount of applicants per week. In the third column, I wish to get the average of the number of applicants this week and all the weeks prior. So if I have three rows, the first average will only use the the first row's number of applicants, the second row's average will be row 1 + row 2 divided by 2, the third row's average will be the amount of applicants of row 1 + 2 + 3 divided by 3.
There's probably a simple way to achieve this, but I cannot figure it out, and I don't know how to phrase it to find the answer in Google.
I can simply drag the formula down and that works, but I'm using ArrayFormulas everywhere and I'd like this average to be generated automatically as well.