Question: what is the formula for quartile?
Answer: Example: Box and Whisker Plot and Interquartile Range for In this case all the quartiles are between numbers: Quartile 1 (Q1) = (4+4)/2 = 4. Quartile 2 (Q2) = (10+11)/2 = 10.5. Quartile 3 (Q3) = (14+16)/2 = 15.