Upper and lower Quartiles?

[Guest]

Nedd to know the formulas for upper and lower quartile from a set of data.
Looked at the forumla quartile but im not sure whether thats entirely correct.

 

[Paul Lautman]

Nedd to know the formulas for upper and lower quartile from a set of
data. Looked at the forumla quartile but im not sure whether thats
entirely correct.

I just tried some sets of values from an Intermediate GCSE text book and it
doesn't always agree with Excel.

 

[Paul Lautman]

I just tried some sets of values from an Intermediate GCSE text book
and it doesn't always agree with Excel.

Excel doesn't agree with BBC Bitesize either

 

[Mike Middleton]

matt -

Nedd to know the formulas for upper and lower quartile from a set of data.
Looked at the forumla quartile but im not sure whether thats entirely
correct. <

From many previous posts, to explain Excel's somewhat nonstandard way of
computing quartiles and percentiles:
Refer to the built-in Help for the Percentile(array,k) function, where
0<=k<=1. Percentile(array,0) = minimum value in the array of n values.
Percentile(array,1) = maximum value in the array. "If k is not a multiple of
1/(n - 1), PERCENTILE interpolates to determine the value at the k-th
percentile." Quartile(array,1) = Percentile(array,0.25).

For more information, browse to Google Groups and search for "excel
percentile quartile" (without the quotes).

- Mike
www.mikemiddleton.com