Warm Up Problem Ms. Chen is buying pencils for her class. Each pencil costs $0.20. What is the cost if she buys 24 pencils?

Shape of Data Distributions Lesson 12-4

Objectives I can describe a data distribution by its center, spread, and overall shape. I can determine the best measure of center and spread for a set of data.

Vocabulary distribution – shows the arrangement of data values symmetric – if the left side looks like the right side cluster – if a bunch of data is grouped together gaps – where there is no data peak – the most frequently occurring value (mode)

Example 1 Describe the shape of the distribution. The line plot shows the temperature in degrees Fahrenheit in a city over several days. The shape of the distribution is not symmetric. There is a gap from 19-21. There are clusters from 16-18 and 22-25. The peak is at 22. There are no outliers.

Example 2 Describe the shape of the distribution. The box plot shows the number of visitors to a gift shop in one month. (You cannot identify gaps, peaks, or clusters.) Each box and whisker has the same length, so the data is spread evenly. The distribution is symmetric. There are no outliers.

Got It? 1. Describe the shape of the distribution at the right. Use clusters, gaps, peaks, outliers, and symmetry. Underline each word in your answer.

Notes

Example 3 Choose the appropriate measures to describe the center and spread of the distribution. Justify your response based on the shape of the distribution. The data is not symmetric and there is an outlier. The median and IQR are the appropriate measures.

Got It? 2. Choose the appropriate measure of center and spread of the distribution. Justify your response based on the shape of the distribution.