Learning to Calculate Interquartile Range

When we have to find the dispersion in statistics, we use the Interquartile Range( IQR). The IQR is the difference between the third and the first quartile. It is the measure of the dispersion of all the values of the range. We can use the quartile calculator to find the value of the quartile. 

The formula we use to find the  Interquartile Range( IQR) is subtracting the values of the third quartile from the first quartile. If you are having a problem, how to find quartiles, then you can use the quartile calculator by calculator-online.net to find the values of the quartile.

                                             IQR=Q3- Q1

You may wonder how to find quartiles of a given data, there is a different method of finding the  Interquartile Range( IQR) of even and odd numbers of data.

Method of finding the Interquartile Range( IQR) for odd quartile:

Order the data in a sequence: When you are finding the Interquartile Range( IQR) for the odd number first you have to arrange the data in a sequence from the least to the greatest:

Now given set of the data is: 5,3,4,11,9,7,12,17,25,27,44

Order the number in a sequence: 3,4,5,7,9,11,12,17,25,27,44

Find the median: Now find the median of the data set, the median of the data set is the middle value of the given data, in this case, the median of the data is “11”.

The median of the data set is given below as:                            

                         3,4,5,7,9,11,12,17,25,27,44

Place the brackets: 

Now place the brackets to the data set:

                            (3,4,5,7,9),11,(12,17,25,27,44)

Find the median of both the quartiles: Now find the median of the lower and upper half of the data. The  middle of the lower quartile is represented by Q1and the upper quartile is represented by Q3

         Q1= (3,4,5,7,9)= 5  The median of the lower quartile 

        Q3= (12,17,25,27,44)= 25  The median of the upper quartile 

The third quartile calculator can make o find the value of  Q3 a little easier for you.

Subtract the ranges: Now subtract the ranges from the upper quartile  Q3 the lower quartile, We can find the  Interquartile Range( IQR):

                     IQR=Q3- Q1= 25-5=20

The quartile calculator calculate the whole process for the odd quartiles

Method of finding the Interquartile Range( IQR) for even quartile:

Order the data in a sequence:You have to arrange the data in a sequence from the least to the greatest:

Now given set of the data is: 30,32,34,36,44,46,2,3,4,24,25,26,

Order the number in a sequence: 2,3,4,24,25,26,30,32,34,36,44,46

Make a mark at the center: Try to palace mark at the center of the data                           

                                        2,3,4,24,25,26,30,32,34,36,44,46

Place the brackets:

Now place the brackets to the data set:

                                    (2,3,4,24,25,26)(30,32,34,36,44,46)

Find the median of both the quartiles: Now find the median of the lower and upper half of the data. The average of the middle numbers is used in even quartiles  

         (2,3,4,24,25,26)=(4+24/2)= 14= Q1 median of the lower quartile 

         (30,32,34,36,44,46)=(34+36/2)= 35= Q3median of the upper quartile 

You can also use the upper quartile calculator to find out the upper quartile.

Subtract the ranges: Now subtract the ranges from the upper quartile  Q3 the lower quartile, We can find the  Interquartile Range( IQR):

                     IQR=Q3- Q1= 35-14=21

The quartile calculator calculates the whole process for the even quartiles, and you can find the IQR of even quartiles.