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What is an outlier in Math?

An outlier is a number in a data set that is much smaller or larger than the other numbers in the data set.

15 would be an outlier in this data set.


In this data set, 90 would be considered an outlier

The measure of center may be affected by an outlier.

Determine how the outlier affects the median and the mean in the
following scores.

35, 90, 88, 93, 96

The outlier in this data set is 35

Determine how the outlier affects the median by finding the median without the outlier included.

The median without the outlier = The average of 88 + 93 = 90.5
How much did the median change? 90.5 – 88 = 2.5

Next, determine how the outlier affects the mean by finding the mean
without the outlier included.

Mean without the outlier = 90 + 88 + 93 + 96 = 91.75

The mean changed by 11.35 91.75-80.4 = 11.35

The mean was changed the most by the outlier.

In conclusion, when comparing the measure of center, and you have an outlier it is best to use the median.

If you have don’t have an outlier then use the mean when finding the measure of center.

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Middle School Math

Identify the outlier in the following data sets.

Keywords: outlier in Math |  | 6th Grade Math | Measure of center | Impact of outlier on measure of center