•What is a box-and-whisker plot?•5-number summary

•Quartile•1st, 2nd, and 3rd quartiles

•Interquartile Range•Outliers

What is a Box-and-Whisker Plot?A box-and-whisker plot is a way of graphically

depicting groups of numerical data through their 5-number summaries.

Box-and-whisker plots are also known simply as:

~Box Plots

Either term is acceptable.

Five-number SummaryThe five number summary is a set of numbers

calculated from your collected data or numbers.

5-number summary consists of:Minimum- lowest observed valueQuartile 1 or Q1Median, also called Q2Quartile 3 or Q3Maximum- highest observed value

QuartileA quartile is the value of the boundary at the

20th, 50th, or 75th percentiles of a distribution divided into four parts.

Each quartile contains a quarter of the data.

1st, 2nd, and 3rd QuartilesThe first quartile, Q1, consists of the lower

25% of the data

The second quartile, median or Q2, is the middle of the data. Also, it can be called the 50th percentile. Half of the data falls on either side of this number.

The third quartile, Q3, contains the upper 25% of the data.

Interquartile Range and OutliersInterquartile range is the difference between

quartile 3, Q3, and quartile 1, Q1.Q3-Q1=IQR

What can you do with the IQR?IQR helps in finding outliersOutliers are data that fall outside the distribution

trend of data.

Q1-(1.5*IQR)= Lower outliersQ3+(1.5*IQR)= Upper Outliers

What does a Box-and-Whisker Plot Look Like?