In this question why does the average trick work?
(1st value + Last value )/n
Isn’t this only true for symmetrical set or evenly spaced set?
What do you think you are supposed to find?
Average change
Does it have to be average change?
Correct, and what exactly does that entail?
Well what if the change is in even ?
It doesn’t work for such a case when the set is not evenly spaced.
You’re on the wrong track. Let y_{2010} be the coffee consumption for Norway in 2010. We need to find
\frac{(y_{2010} - y_{2012}) + (y_{2012} - y_{2014}) + ... + (y_{2018} - y_{2020})}{5}
Spot a shortcut.
what if the differences are not equal then median is not gonna be equal to the mean so mean will move right or left ?
Does not matter. Try computing this explicitly.
Oh I get it.
I didn’t notice that…
Noice
But what about the 5 below?
We’re looking for the average - so dividing by number of diffs.
Ok I got it, Thanks