A box plot (box and whisker plot) summarises a data set with five numbers: minimum, Q1, median, Q3, maximum. You can compare two distributions at a glance.
How to read it
- Box — middle 50% of the data (Q1 to Q3)
- Line in the box — median
- Whiskers — reach to the smallest and largest values within 1.5 × IQR
- Dots beyond whiskers — outliers worth investigating