1. Lesson 8.1.1 – Teacher Notes Standard:
7.SP.B.3 Informally assess the degree of visual overlap of two numerical data distributions with similar variabilities, measuring the difference between the centers by expressing it as a multiple of a measure of variability. For example, the mean height of players on the basketball team is 10 cm greater than the mean height of players on the soccer team, about twice the variability (mean absolute deviation) on either team; on a dot plot, the separation between the two distributions of heights is noticeable.
Full mastery can be expected by the end of the chapter.
Lesson Focus:
The focus of this lesson is to refresh 6th grade skill of histograms, box plots, measures of center, variability, and shape. Problems 8-1 to 8-4 could be skipped or consolidated to shorten the lesson to one day. The emphasis needs to be placed on comparing data sets. (8-5, particularly part c)
I can compare two numerical data distributions on a graph by visually comparing data displays, and assessing the degree of visual overlap.
Calculator: Yes
Literacy/Teaching Strategy: Turn and Talk (Whole lesson); Huddle (Struggling Learners)

2. Bell Work

3. Do the lengths of the object you are measuring or the tool you choose to measure with affect how precise your measurement is likely to be?  In this section, your class will explore this question by analyzing the results of an experiment.  As you work with your team, think about the questions that follow.
What am I measuring?
What unit is being repeated?
What can I do to make my measurement more precise?

4. Your Task: As directed by your teacher, measure the specified length in the classroom to the nearest inch twice, each time using a different tool (a 12-inch ruler and a single measuring tape, for example).  Although you will share tools with your team and work together to make sure the measures are recorded properly, each person in the team should measure the length twice, once with each tool.
8-5. Creating visual representations of data makes data sets easier to compare.
Make a histogram for each set of data. Make sure to use the same scale for both histograms. 
Create box plots for the two sets of data. Put both box plots on the same number line and use the same scale as you did for your histogram.   

5. Your Task: As directed by your teacher, measure the specified length in the classroom to the nearest inch twice, each time using a different tool (a 12-inch ruler and a single measuring tape, for example).  Although you will share tools with your team and work together to make sure the measures are recorded properly, each person in the team should measure the length twice, once with each tool.
8-5. Creating visual representations of data makes data sets easier to compare. 
Compare the center, shape, spread, and outliers for the two sets of data using the histograms and the box plots. Do the data sets seem to show the same value for the length of the classroom?

6. What is the mean of class A?
For what values do class A's distribution and class B's distribution overlap?
Which measure could be used to compare the centers of the distributions?
Which measure could be used to compare the spread of the two distributions?
What is the mean of class A?
What is the interquartile range of class B?
Using the interquartile range of each class, compare the variabilities of the two classes.
ANSWERS ARE HERE!!

7. Practice
Jason is comparing the height of players on his favorite soccer and basketball teams. He organized the information below.
What is the range for each set of team?  
What is the median for each team? 
Does either team have an outlier? If so, list it.
Which team is taller?
Explain how you know.

8. Practice
This table shows the marks (out of 50) obtained in some tests by two pupils:
Use the range and mean to decide which pupil is better.