For use with the October 2010 issue, pages 12–13.
✔
Median: The middle number in an ordered set of numbers. (If there are two middle numbers, add them and
divide by two to get the median.)
✔ Mode: The number in a set that appears most often. There can be more than one mode.
✔ Outlier: A number that is very far from the other numbers in a set. There won’t always be an outlier.
✔ To find the median, mode, and outlier
of a set, you can make a line plot.
Example: What is the median, mode, and outlier for this set: 10, 20, 10, 15, 25, 15, 25, 55, and 10? x x x x x x x x
10 15 20 25 30 35 40 45 50 55
✔ To find the median, count the X’s, starting at the left. The median is the middle number. There are 9 numbers in the set in the line plot above so the middle
number is the fifth number. Median = 15.
✔ The number 10 has the most X’s. Mode = 10.
✔ The outlier is 55—it is far from the other numbers.
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