I had a previous problem that was solved that was similar, but wasn’t a running total: Excel formula for declining number, in 5 year intervals
So this number is about budge forecasting. It needs to include the average annual inflation rate. The parts that are tricky for me, is that I need it to be in 5 year increments and it needs to be cumulative (meaning, it keeps adding the previous amounts with the current year).
For example, let’s say in 2020 the budget is $100. Average annual inflation rate is 3%. In 2021, the budget is $113. That running total in 2005 is 531 (so that means years 2020, 2021, 2022, 2023, 2024 is 100, 103, 106, 109, and 113 respectfully. So how would I create a repeating formula that tabulates like this that only shows every 5 years (in other words, I don’t want 5 rows, just one for every 5 year increment).