Eight pupils read 15, 3, 9, 1, 12, 6, 20 and 7 pages. What is the median number of pages? Enter the number of pages.
Correct answer
8 · Accepted units: pages
Explanation
Sorted by size, the eight counts run 1, 3, 6, 7, 9, 12, 15 and 20, and the two central positions of eight hold 7 and 9, whose mean is 8 pages. Averaging the pair that stand in the middle of the list as recorded, 1 and 12, gives 6.5 instead, because that pair was never ranked by size.