1. Box-and-whisker plots & Dot Plots

2. How to read a box-and-whisker plot.
Dots outside of the box and whiskers are outliers.
Maximum and minimum values are shown at the ends of each whisker.
The upper and lower quartiles are the ends of the box.
The median is the line in the middle of the box.
Outlier
Minimum
Lower quartile
Median
Upper quartile
Maximum
Outlier

3. Example 1
Ruby asked the students in her class how long their families spent making dinner each night. This box-and-whisker plot shows the results.
Find the following values:
Minimum: LQ: Maximum: UQ:
Range: Interquartile Range: Median: 20 25 50 45 30 20 35

4. Practice Problem 1
A professor asked her students to keep track of how many websites they visit each day. This box-and-whisker plot shows the results.
Find the following values:
Minimum: LQ: Maximum: UQ:
Range: Interquartile Range: Median: 4 5 8 10 6 3 7

5. How to read dot plots
The dots above each number represent a number in the data set.
If dots are stacked on top of each other, that means that the value occurs more than once.
Labeling the axis is key to determining the numbers in the data set.

6. Example 2
From the dot plot below, you can see that there are few values near the maximum and minimum values.
There are clusters of values between 64 and 80.
You can infer that for this dot plot, most people’s pulses were between 64bpm and 80 bpm.

7. Comparing two dot plots
The dotplots to the right show pet ownership in two city blocks.
As seen in the graph, pet ownership in block a is lower.
In block a, the amount of pets that people own ranges between 0 and 4.
In block b, most households have two or more pets.
In block b, the amount of pet ranges between 0 and 6.

8. Practice Problem
The dot plot below shows the age of actors and actresses who win awards. Make a prediction about the ages of actresses and actors in the dot plots below.
Actresses win more awards than actors at a younger age.
Actors win more awards than actresses at an older age.