Interquartile Range Example:
5,3,9,8,7,1,2,3
1- Put the numbers in order: 1,2,3,3,5,7,8,9
2- 1/4 multiplied by the amount of numbers there are: 1/4 multiplied by 8
3- 1/4 multiplied by 8 is 2.
4- Because the answer is even (2) u will take the 2nd and 3rd number and add them and divide by 2. If number was (2.5 or 3.7 or anything that is not a whole number) round up. So if number was 3.7 u will get the 4th number in the list of number.
5- 2+3=5. 5/2= 2.5. 2.5 is your lower quartile (Q1)
6- Now get 3/4 of the numbers.
7- 3/4 multiplied by 8 = 6
8- Get 6th and 7th number and again divide by 2.
9- 7+8 = 15. 15/2 = 7.5 . 7.5 is your upper quartile (Q3)
10- Finally (Q3) 7.5 - (Q1) 2.5. Answer is 5
Hope this helps:)

Study2000— 11/06/16