Also why find the median and IQR
2007-11-01 04:58:08 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
For data that is strongly skewed, the mean in a misleading measure of central tendency and the median is more appropriate.
And since the median is the 50th percentile, then once a person decides to use the median, the appropriate way to describe how the data varies is to talk about percentiles (as opposed to standard deviation, which is based on the mean.)
One reason to talk about the quartiles is that they are percentiles that are easy to find! The earlier poster rightly points out another reason, that they mark off the central 50% of the data, and thus hopefully mark off the "typical" data.
But you could also find the first and fourth quintiles, and thus find the central 60% of the data. There is nothing carved in stone about quartiles.
2007-11-01 05:17:35 · answer #1 · answered by Michael M 7 · 1⤊ 0⤋
Median and quartiles give you a simple picture of how the data is distributed. Why should you find them? Well, if you want to know how the data is distributed.
More generally, you should find them because your teacher asked you to do so, because right now you don't know enough about the world or your future to be able to say which information will be useful, and because by keeping your mind open enough to learn things for which you personally have no immediate use, you develop the habit of being openminded, widely informed, and tolerant -- all of which are critical survival skills. The alternative is political, ecological, technological catastrophe.
2007-11-01 05:19:05 · answer #2 · answered by Philo 7 · 0⤊ 0⤋
The space between the upper an lower quartile shows 50% of the data. you find the IQR to determine if there are out liars. you find the median so you can find the quartiles.
hopes that helps.
2007-11-01 05:04:00 · answer #3 · answered by Anonymous · 1⤊ 1⤋
To find the interquartile range. The inter-quartile range shows you the middle 50% of data.
2007-11-01 20:10:23 · answer #4 · answered by sweet_angel92 3 · 0⤊ 0⤋
Unless the question specifies that u need to find, you do not have to.
Statistically, they are figures used for higher level analysis, which i believe that u will not appreciate given that u can ask such a question here.
2007-11-01 05:12:03 · answer #5 · answered by Anonymous · 1⤊ 0⤋
if not asked why bother??? dont find it then lol
2007-11-01 06:18:38 · answer #6 · answered by vfm 3 · 0⤊ 0⤋
Because if you don't, you won't get credit.
2007-11-01 05:11:34 · answer #7 · answered by Dr D 7 · 1⤊ 3⤋