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Lesson 3 of 14

The middle one, once they are in order

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Buses counted after school on five days: 12, 7, 15, 9, 11. Which one is the middle?

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Sorted, smallest to largest: 7, 9, 11, 12, 15.
Step 1 of 3
  1. Sorted, smallest to largest: 7, 9, 11, 12, 15.
  2. Cross off the smallest and the largest: 7 and 15 go.
  3. Cross off the new ends: 9 and 12 go. 11 survives.

The middle count is 11 once the counts are in order.

Put the readings in order first. Then cross off one from each end. Repeat until one is left. The one left is the median.

Each round removes one reading from each end. So the median has as many places before it as after it.

Try the lab to finish this lesson.