Re: {mg3340] quartile
- To: mathgroup at smc.vnet.net
- Subject: [mg3373] Re: {mg3340] quartile
- From: Lou Talman <me at talmanl.mscd.edu>
- Date: Sat, 2 Mar 1996 04:14:20 -0500
- Sender: owner-wri-mathgroup at wolfram.com
Bryce Kelly wrote:
> On Mathematica's definition of a quartile.
>
> Hello All,
>
> I need some help on the definition of a quartile. I have run into the
> following problem on different definitions for quartiles between Maple
> and Mathematica .
>
> Using Mathematica 2.2.1
> In[] := <<Statistic`DescriptiveStatistics`
> In[] := data = {10,20,30,40,50,60,70,80}
> In[] := Median[data]
> Out[] = 45
> In[] := Quartiles[data]
> Out[] = {25,45,65}
>
> Using Maple V release 4
> > data := [10,20,30,40,50,60,70,80]:
> > with(stats):
> > with(describe):
> > median(data);
> 45
> > quartiles := [seq(describe[quartile[i]],i=1..3)]:
> > quartiles(data);
> [20,40,60]
>
> What is Mathematica source for the definition of a quartile ?
>
One might better ask for the source of Maple's definition of "quartile". I've
never seen a definition of "quartile" that made the second quartile different
from the median. And most folks I know would agree that the first and third
quartiles should be the medians of the lower and upper halves of the data--as
Mathematica appears to think.
--Lou Talman
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