Hi everyone,
Sorry if this question is too random or general, but itīs bugging me.
Why do we write the mean absolute variation like this:
and not like this?:
i.e. why do we multiply the sum of deviations by 1/N, instead of just dividing the sum of deviations by N?
Thanks
Aidan,
Sorry, I wasnīt clear... they are the same, which is my point. The first one seems to me to add another layer of non-intuitive complexity that bugs beginners like me... I wondered if there was a purpose to it that I havenīt caught.
Thanks for replying.
The difference is not mathematical but typographical: the version with 1/N looks more elegant and takes up less space. Back in the days of manual typesetting, printers hated large build-up fractions, and encouraged copy-editors and authors to avoid them where possible. Now that everyone uses TeX, that's not so much of an issue, but old preferences linger on.