Interquartile range equals?

Interquartile range equals?

• A. Q3 - Q1
• B. Q2 - Q1
• C. Q3 - Q2
• D. Mean - Median

Answer: (A)

Interquartile range measures the spread of the middle 50% of the data. It is found by subtracting the first quartile from the third quartile: IQR = Q3 − Q1. This focuses on the central portion of the distribution and is less affected by outliers than the overall range. So the correct expression is Q3 minus Q1. The difference between the median and the first quartile (Q2 − Q1) isn’t the central spread, and the difference between the third quartile and the median (Q3 − Q2) also doesn’t represent the central 50% spread. Mean minus median relates to a central tendency, not spread.

Interquartile range measures the spread of the middle 50% of the data. It is found by subtracting the first quartile from the third quartile: IQR = Q3 − Q1. This focuses on the central portion of the distribution and is less affected by outliers than the overall range.

So the correct expression is Q3 minus Q1. The difference between the median and the first quartile (Q2 − Q1) isn’t the central spread, and the difference between the third quartile and the median (Q3 − Q2) also doesn’t represent the central 50% spread. Mean minus median relates to a central tendency, not spread.