My basic objective is to look up the cost per month of each project in the previous months and print the average YTD cost in that month in Col F.
For example Project A cost per month in April is 10. In May if it is 20, then in the next column of YTD average, April Cost will be same since it is the first month i.e 10. But in May it will be 15 ((10+20)/2).
Please refer attached xls for reference forum.ozgrid.com/index.php?attachment/62559/.
I tried to use nested ifs with vlookups but not getting anywhere.
Please note there are 50+ projects across 12 months in my data, hence simple average formula that I have use for the example wont work.