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Searching for ## Measures of Central Tendency

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Math Foundations

You will use box-and-whisker plots for representing and displaying relationships among collected data.

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After completing this tutorial, you will be able to complete the following:

- Use real-world data to construct box-and-whisker plots.
- Answer questions about data displayed on a box-and-whisker plot.
- Interpret data displayed on a box-and-whisker plot.

A box-and-whisker plot is a graphical display of data that organizes a data set in such a way that the data are split into four equal parts, accounting for 25% of the entire data set. Box-and-whisker plots help to show how spread out the data are.

A five-number summary is another name for the visual representation of the box-and-whisker plot, which includes the lower extreme, lower quartile, median, upper quartile and upper extreme.

The lower extreme is the lowest number, and the upper extreme is the highest number, in a data set. The median is the value that divides a data set into two equal parts. When the ordered set has an even number of values, find the average of the two middle numbers. The lower quartile is the median of the lower half of the data, and the upper quartile is the median of the upper half of the data.

For example, given the data set of 20, 32, 40, 60, 64, 72, and 80, the lower extreme would be 20, and the upper extreme would be 80. The median would be 60. Once the median for the ordered set is found, consider only the values to the left of the median to find the lower quartile. The lower quartile would be 32. Once the median for the ordered set is found, consider only the values to the right of the median to find the upper quartile. The upper quartile of this data set would be 72.

The following plot represents the data set of 20, 32, 40, 60, 64, 72, and 80.

Approximate Time | 25 Minutes |

Pre-requisite Concepts | Students should be familiar with line plots, mean, and median. |

Course | Math Foundations |

Type of Tutorial | Concept Development |

Key Vocabulary | box-and-whisker plot,, |