[ELI5] Why average of 12 months growth percentile is not the same as sum of growth percetnile?

Question

Jan 2022 sales 100
Jan 2021 sales 50

Feb 2022 sales 150
Feb 2021 sales 90

Jan sales growth is 100%
Feb sales growth is 67%
Average growth **83%**

2022 sales total 250
2021 sales total 140
Percent growth is **79%**

Why do i feel stupid, ama grown ass man and i cnt figure it out

In: 0

Answer 1

You might be talking about the Simpson’s Paradox – the average of some averages is not the average -> https://lemire.me/blog/2005/10/28/average-of-averages-is-not-the-average/