Median weight of 40 female lions from a grouped frequency table (118-126 to 172-180 kg)

There are 40 lions, so the median is at the 20th value. Add the frequencies: 3, 8, 17, 29, … The running total reaches 17 before the class 145 – 153 and 29 after it, so the median lies in 145 – 153.

Use the class boundaries. The lower boundary is 144.5 and the class width is 9. Median = 144.5 + ((20 – 17) ÷ 12) × 9 = 144.5 + 2.25 = 146.75 ≈ 146.8 kg.

The middle of the class, 149, is tempting, but it ignores where the 20th value actually falls inside the class.