Q:
# How Is the Interquartile Range Determined?

**The interquartile range, or IQR, can be found after the median has been determined by dividing the data sets that are above and below the median in half, which divides the entire set into quarters, and then combining the second quarter with the third quarter.** The resulting range is the IQR and represents the middle 50 percent of the entire data range. This splits the data set into three ranges, or quartiles: the first quartile (Q_{1}) is the 25 percent of the data range below the IQR, the third quartile (Q_{3}) is the 25 percent of the data range above the IQR and the IQR can be described as Q_{3} subtracted from Q_{1}.

The IQR is also called the "middle fifty" or the "midspread" and is used to measure statistical dispersion in descriptive statistics. When a box plot is made of the data, the three quartiles can be easily seen as a graphical representation of a probability distribution. A useful application of the interquartile range is to determine the outliers in data.

Descriptive statistics, in which the IQR plays an important role, involves the organizing and summarizing of data so that it can be more easily understood. Unlike inferential statistics, the objective of descriptive statistics is to describe data without attempting to make inferences from the sample being examined to the entire population.

Learn more about Statistics-
Q:
## What Is "IQR"?

A: IQR stands for "interquartile range," a measurement of the location of the bulk of values in a set of data. The formula for finding the interquartile range... Full Answer >Filed Under: -
Q:
## How Do I Calculate the Upper or Lower Quartile?

A: To find the first quartile of a set of numbers, find the median of the lowest half of the data set. This median is the first, or lowest, quartile in the da... Full Answer >Filed Under: -
Q:
## How Do You Calculate the Median of a Set of Numbers?

A: Calculate the median of a set by putting the numbers in order from least to greatest and finding the middle number, when there is an odd number of values i... Full Answer >Filed Under: -
Q:
## What Is the Difference Between Mean, Median, Mode and Range?

A: Mean, median and mode are different ways of determining the average from a set of numbers. Range gives the difference between the highest and lowest values... Full Answer >Filed Under: