Which measure of spread is most commonly used with the median?

• A. Range
• B. Interquartile Range
• C. Standard Deviation
• D. Variance

Answer: (B)

The main idea is that when you use the median as the center, you want a spread measure that isn’t swayed by outliers or skewed data. The interquartile range does exactly that by capturing the spread of the middle 50% of the data (the difference between the 75th and 25th percentiles). Because it focuses on the central portion, it stays stable even if there are extreme values or a skewed distribution, making it the best match for the median. Other measures like the range, standard deviation, or variance are more affected by extreme values or assume a roughly symmetric distribution, so they can give a distorted sense of spread when paired with the median. That’s why the interquartile range is the most appropriate choice here.