# how do I calculate a median?

as opposed to a mean

say my data set is [1,2,5,3,6,2,2,4,5,2,2,3,1,8]
ed.davey
10 March 2011
First of all you have to sort the numbers into order
theo.cushion
10 March 2011
how do I do that?
ed.davey
10 March 2011
[1,2,5,3,6,2,2,4,5,2,2,3,1,8].sort
theo.cushion
10 March 2011
[1, 1, 2, 2, 2, 2, 2, 3, 3, 4, 5, 5, 6, 8]
theo.cushion
10 March 2011
then what?
ed.davey
10 March 2011
?
ed.davey
10 March 2011
Then you need to find the middle value
theo.cushion
10 March 2011
using a ruler?
ed.davey
10 March 2011
so you have 14 values
theo.cushion
10 March 2011
take the middle 2 values number 7 and 8
theo.cushion
10 March 2011
so that is values 3 and 4
theo.cushion
10 March 2011
so \$ frac{3 + 4}{2} = 3.5\$
theo.cushion
10 March 2011
so is the median 3 and 4 or 3.5?
ed.davey
10 March 2011
You've got it!
theo.cushion
10 March 2011
Sorry, its 3.5
theo.cushion
10 March 2011
This is OK
ed.davey
10 March 2011
thanks
ed.davey
10 March 2011
That private session really helped
ed.davey
10 March 2011
ed.davey
10 March 2011
I'm stll unclear on this
ed.davey
12 January 2012
Hoping that someone can give me a bit more guidance on this topic...
ed.davey
12 January 2012
Hi, basically, you arrange your numbers in order and then pick the middle one. That's called the median. I you have an even number of numbers, though, like in your example, then there are 2 in the middle, so find the number half-way between them.
miriam
14 January 2012
Sorry, 3rd sentence should have been "If" at the start, not "I".
miriam
14 January 2012