The mathematical purpose of this lesson is to compare data sets with different measures of variability and to interpret data sets with greater MADs or IQRs as having greater variability. Students make connections between different data displays and measures of center and measures of variability. This lesson builds on previous work by using what students learned when creating data displays and determining which measure of center is appropriate. In upcoming lessons, students will use their understanding of MAD to figure out the meaning of standard deviation. When students match data displays with descriptions of shape, measures of center, or measures of variability they are engaging in MP2 because they are having to makes sense of the data display and the corresponding description or measure. When students participate in a math talk about finding the mean, they have an opportunity to notice and make use of the symmetric structure (MP7) of the values to determine the mean. Additionally, students need to be precise in their word choice and use of language (MP6). In the take turns activity students trade roles explaining their thinking and listening, providing opportunities to explain their reasoning and critique the reasoning of others (MP3).
- Interpret (orally) a data set with greater MAD or IQR as having greater variability.
- Let’s investigate variability using data displays and summary statistics.
Print and cut up slips from the blackline master. Prepare 1 copy for every 2 students.
- I can arrange data sets in order of variability given graphic representations.
A quantity that is calculated from sample data, such as mean, median, or MAD (mean absolute deviation).