Question: How can one compute a mean?

If I have a set of numbers,

1, 2, 3, 4, 5

for example, how do I compute their mean?

How do I compute their standard deviation?

I am trying to avoid explicitly recopying cutting and pasting

my data over and over again, such as

a:= (1 + 2 + 3 + 4 +5 )/ 5;

sdev: = sqrt( (a-1)^2 + (a-2)^2 etc.

My REAL question is: WHERE in Maple 11 Help is an example shown anywhere of an explicit finite data set of numbers, such as 1, 2, 3, 4,5, or a set of pairs of numbers (2,3), (4,5) etc 

I already know the answer to that question: it is not anywhere in Maple 11 Help.

This is an absolute 100% guaranteed true fact.

All you get out of Maple 11 Statistics Package help menu is endless endless Array Matrix Vector garbage

that just spews back one's Array Matrix Vector whatever with a whole of datatype garbage listed after it. It is physically impossible to do anything with that data, such as compute a mean or standard deviation.