KeenRegard

As a super, super important captain of business and industry, I need a system that will do the 
following for my business:

I need `sum`, `mean`, and `median` to perform certain functions on my very important sets of 
numbers. I need allof them to perform these actions and need to ensure I do not have the 
same problem my LAST team caused. Those now-unemployed so-and-sos screwed up big time 
(and cost me millions of dollars!) by not taking into account the fact that my number sets
can contain an even OR an odd number of elements!

So I need my number sets that have an even number of elements (say, `evenLengthArray`)