The QUARTILE.EXC function returns the quartile of the data set, based on percentile values from 0…1, exclusive.
 This function was introduced in Excel 2010 and so is not available in earlier versions.
Syntax
=QUARTILE.EXC(array,quart)
Arguments
Argument  Description  

array  The range of data values for which you want to calculate the specified quartile  
quart  An integer between 1 and 3, representing the required quartile

Note: The QUARTILE.EXC function can’t calculate the 0’th or the 4’th quartile as the calculation is based on the range 0 to 1 exclusive.
If the requested quartile falls between two of the values in the supplied array, Excel interpolates between these values to calculate the quartile value.
Examples
A  B  C  D  E  

1  Data  Formula  Result  Notes  
2  9  =QUARTILE.EXC(A2:A10,1)  11.5  Locates the position of the first quartile  
3  37  =QUARTILE.EXC(A2:A10,2)  20  Locates the position of the second quartile  
4  6  =QUARTILE.EXC(A2:A10,3)  32  Locates the position of the third quartile  
5  16  
6  26  
7  32  
8  32  
9  14 
Note: The Quartile.Inc function is closely related to the PERCENTILE.EXC such that:
 The 1st quartile is the same as the 25th percentile
 The 2nd quartile is the same as the 50th percentile
 The 3rd quartile is the same as the 75th percentile
Common Function Error(s)
Problem  What went wrong  

#VALUE!  Occurs if the supplied value of quart cannot be interpreted as a numeric value  
#NUM!  Occurs if either:

The 1st, 2nd, 3rd or 4th quartile of a range of data is the value that 25%, 50%, 75% or 100% (respectively) of the data values fall within.
The QUARTILE.INC and QUARTILE.EXC functions both find a requested quartile of a supplied data set. The difference between these two functions is that the QUARTILE.INC function bases its calculation on a percentile range of 0 to 1 inclusive, while the QUARTILE.EXE function bases its calculation on a percentile range of 0 to 1 exclusive.
See Wikipedia for more information on quartile.