The quartile formula helps in calculating the value that divides a list of numbers into quarters. The data is firstly arranged into ascending order and is then divided into quartiles. Median divides a given data into two equal parts while quartiles divide it into four parts. Using the quartile formula we can find the first quartile, second quartile, and third quartile.
What is Quartile Formula?
The quartile formula helps to divide a set of observations into 4 equal parts. The first quartile lies in the middle of the first term and the median. The median is the second quartile. The middle value lying between the median and the last term is the third quartile. Mathematically, they are represented as follows,
When the set of observations are arranged in ascending order the quartiles are represented as,
First Quartile(Q1) = ((n + 1)/4)th Term
Second Quartile(Q2) = ((n + 1)/2)th Term
Third Quartile(Q3) = (3(n + 1)/4)th Term
1st quartile is also known as the lower quartile. 2nd quartile is the same as the median dividing data into 2 equal parts. 3rd quartile is also called the upper quartile.
The interquartile range is calculated as Upper Quartile – Lower Quartile.
Break down tough concepts through simple visuals.
Math will no longer be a tough subject, especially when you understand the concepts through visualizations with Cuemath.