# Outliers Explanation

• Nov 3rd 2008, 08:45 PM
22upon7
Outliers Explanation
Ok so here are the data elements:
16,18,21,23,24,25,25,26,27,29,31

My books says that these are the outliers :
16 and 31

BUT how can this be

Q1 = (11+1)*0.25= 3rd element
Third element = 21

Q3 = (11+1)*0.75= 9th element
Ninth element = 27

IQR = Q3 - Q1 = 6

SO OUTLIERS =

Q1 + 1.5 * IQR =
21 + 1.5 * 6 = 30?? There aren't 30 elements?

OR

Q3 - 1.5 * IQR =
27 - 1.5 * 6 = 18 ?? There aren't 18 elements?

• Nov 3rd 2008, 08:55 PM
16 and 31 are the outliers because they are not between 18 and 30.
• Nov 3rd 2008, 08:57 PM
Chris L T521
Quote:

Originally Posted by 22upon7
Ok so here are the data elements:
16,18,21,23,24,25,25,26,27,29,31

My books says that these are the outliers :
16 and 31

BUT how can this be

Q1 = (11+1)*0.25= 3rd element
Third element = 21

Q3 = (11+1)*0.75= 9th element
Ninth element = 27

IQR = Q3 - Q1 = 6

SO OUTLIERS =

Q1 - 1.5 * IQR =
21 - 1.5 * 6 = 18?? There aren't 30 elements?

OR

Q3 + 1.5 * IQR =
27 + 1.5 * 6 = 30?? There aren't 18 elements?