How to Find the IQR
Know how the IQR is used., Understand quartiles., Learn the formula.
Step-by-Step Guide
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Step 1: Know how the IQR is used.
Essentially, it is a way of understanding the spread or "dispersion" of a set of numbers.The interquartile range is defined as the difference between the upper quartile (the highest 25%) and the lower quartile (the lowest 25%) of a data set.
The lower quartile is usually written as Q1, and the upper quartile is Q3 – which would technically make the halfway point of the data set Q2, and the highest point Q4., To visualize a quartile, chop a list of numbers into four equal parts.
Each of these parts is a "quartile."Consider the set: 1, 2, 3, 4, 5, 6, 7,
8. 1 and 2 are the first quartile, or Q1 3 and 4 are the second quartile, or Q2 5 and 6 are the third quartile, or Q3 7 and 8 are the fourth quartile, or Q4 , In order to find the difference between the upper and lower quartile, you'll need to subtract the 75th percentile from the 25th percentile.
The formula is written as:
Q3 – Q1 = IQR. -
Step 2: Understand quartiles.
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Step 3: Learn the formula.
Detailed Guide
Essentially, it is a way of understanding the spread or "dispersion" of a set of numbers.The interquartile range is defined as the difference between the upper quartile (the highest 25%) and the lower quartile (the lowest 25%) of a data set.
The lower quartile is usually written as Q1, and the upper quartile is Q3 – which would technically make the halfway point of the data set Q2, and the highest point Q4., To visualize a quartile, chop a list of numbers into four equal parts.
Each of these parts is a "quartile."Consider the set: 1, 2, 3, 4, 5, 6, 7,
8. 1 and 2 are the first quartile, or Q1 3 and 4 are the second quartile, or Q2 5 and 6 are the third quartile, or Q3 7 and 8 are the fourth quartile, or Q4 , In order to find the difference between the upper and lower quartile, you'll need to subtract the 75th percentile from the 25th percentile.
The formula is written as:
Q3 – Q1 = IQR.
About the Author
Joan Johnson
Joan Johnson has dedicated 13 years to mastering lifestyle and practical guides. As a content creator, Joan focuses on providing actionable tips and step-by-step guides.
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