Lesson · M.2.2

Mean, median, mode, and range

How to calculate mean, median, mode, and range on the TEAS, and why an outlier changes some of these measures but not others.

ObjectiveM.2.2Read2 minExam weightMeasurement and Data ≈ 47% of Mathematics

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What you will be able to do

  • Calculate the mean, median, mode, and range for a data set.
  • Order a data set before locating its median value.
  • Predict how an outlier affects the mean, median, mode, and range differently.

What the lesson concludes

  • Mean is the total divided by the count; median is the middle value once ordered; mode is the most frequent value; range is the largest value minus the smallest.
  • Order the set first before finding the median, since the raw list order does not matter.
  • An outlier pulls the mean and stretches the range but leaves the median and mode largely unaffected.
  • A set can have no mode, one mode, or several, so do not assume every set has exactly one.
  • When a question mentions "average", it means the mean, unless it specifically says median or mode.