Texas Algebra Texas Algebra II

Unit 3: Unit 3: Probability/StatisticsProbability/Statistics

Lesson 28: Box and Whiskers plots

Lesson Objectives:Lesson Objectives:TEKSTEKS

The student will be able to:1. Define Box and Whiskers Plot and identify key

components2. Define upper quartile, lower quartile and outliers3. Interpret data given in a box and whiskers plot4. Organize a given data set into a box and whiskers plot5. Use a stem and leaf plot to identify/calculate the median,

upper quartile, and lower quartile of a data set

DefinitionsDefinitions• Box and Whiskers Plot - A visual display of the five

number summary, the upper and lower quartiles, the median, and the minimum and maximum values. The box-and-whisker plot is a simplified boxplot taught to beginners . May or may not include outliers.

• upper quartile- For a set of data, a number for which 25% of the data is more than that number.

• lower quartile- For a set of data, a number for which 25% of the data is less than that number.

• Outliers- *A data point that is distinctly separate from the rest of the data.

*One definition of outlier is any data point more than 1.5 interquartile ranges (IQRs) below the first quartile or above the third quartile.

Box plotBox plotThis is a box and whiskers plot.

Maximum(upper extreme)

Upper quartilemedian

Minimum(lower extreme)

Upper quartile

Putting given set in Putting given set in plotplot

Here is the data set:

{25, 45, 89, 45, 42, 23, 74, 45, 28, 52, 36, 25, 38, 69, 23}

1. Order your number set

2. Find the median3. Find your upper and

lower quartiles4. Draw your box5. Complete by

extending the whiskers out to the maximum and minimum values

Putting given set in Putting given set in plotplot

Second example:

{5, 4, 8, 9, 4, 5, 4, 2, 2, 3, 7, 4, 4, 5, 6, 9, 2, 3}

1. Order your number set

2. Find the median3. Find your upper and

lower quartiles4. Draw your box5. Complete by

extending the whiskers out to the maximum and minimum values

Lesson Objectives:Lesson Objectives:TEKSTEKS

The student will be able to:1. Define Box and Whiskers Plot and identify key

components2. Define upper quartile, lower quartile and outliers3. Interpret data given in a box and whiskers plot4. Organize a given data set into a box and whiskers plot5. Use a stem and leaf plot to identify/calculate the median,

upper quartile, and lower quartile of a data set