Statistics

Lesson 4

Math

Unit 7

7th Grade

Lesson 4 of 9

Objective


Analyze data sets using measures of center and measures of variability.

Common Core Standards


Core Standards

  • 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.
  • 7.SP.B.4 — Use measures of center and measures of variability for numerical data from random samples to draw informal comparative inferences about two populations. For example, decide whether the words in a chapter of a seventh-grade science book are generally longer than the words in a chapter of a fourth-grade science book.

Foundational Standards

  • 6.SP.A.2
  • 6.SP.A.3

Criteria for Success


  1. Find measures of center of a data set, including the mean and the median.
  2. Find measures of variability of a data set, including the range, interquartile range, and mean absolute deviation (MAD) of a data set.  
  3. Interpret measures of center and variability in context of the populations they are measuring.
     

Tips for Teachers


This lesson is approaching standards 7.SP.3 and 7.SP.4. It reviews concepts from sixth-grade standards 6.SP.2 and 6.SP.3 in preparation for comparing populations in Topic C. 

Lesson Materials

  • Calculators (1 per student)
Fishtank Plus

Unlock features to optimize your prep time, plan engaging lessons, and monitor student progress.

Anchor Problems

25-30 minutes


Problem 1

Two dot plots are shown below. One dot plot shows student scores on a recent math quiz. The other dot plot shows the ages of people on a field trip

     

For each dot plot, answer the questions below.

a.   Find the mean value.

b.   Find the median value.

c.   Determine which measure of center best represents the typical value in the data set and explain your reasoning.

Guiding Questions

Create a free account or sign in to access the Guiding Questions for this Anchor Problem.

Student Response

Upgrade to Fishtank Plus to view Sample Response.

Problem 2

The cost of items can vary based on where the items are sold. The table below shows the price of the same loaf of bread that is sold at 6 different stores in a neighborhood.

Store A B C D E F
Price in dollars 3.75 4.00 2.15 5.15 3.45 2.50

a.   Find the mean absolute deviation of the price of this bread in this neighborhood, based on these six stores.

b.   A different neighborhood sells the same loaf of bread at several stores. The MAD of the price of bread is 0.65. Do the prices of the loaf of bread vary more or less in this neighborhood compared to the neighborhood in part A? Explain your reasoning.

Guiding Questions

Create a free account or sign in to access the Guiding Questions for this Anchor Problem.

Student Response

Upgrade to Fishtank Plus to view Sample Response.

Problem 3

A teacher recorded the time, in minutes, it took students in two different classes to complete a recent math test. He represented the data in two dot plots, one for each class.

 

a.   Find the median amount of time, in minutes, it took students from each class to complete the math test.

b.   Which class had the least variability in their completion time? Find the interquartile range to support your answer.

Guiding Questions

Create a free account or sign in to access the Guiding Questions for this Anchor Problem.

Student Response

Upgrade to Fishtank Plus to view Sample Response.

Problem Set

15-20 minutes


Give your students more opportunities to practice the skills in this lesson with a downloadable problem set aligned to the daily objective.

Target Task

5-10 minutes


While waiting for their bus to arrive after school one day, 10 students wondered how many baskets from the free-throw line they could each make in 5 minutes. Each student took their turn. The results are shown below:

14,   8,  12,  6,  20,  26,  9,  6,  11,  12

a.   Find the mean and median number of baskets made by the students.

b.   Which measure of center better represents the typical number of baskets made?

c.   Ten players on the co-ed basketball team determined the number of baskets they could make from the free-throw line in 5 minutes. The interquartile range of their data set was 3. Which data set has the greater variability?

Student Response

Upgrade to Fishtank Plus to view Sample Response.

Additional Practice


The following resources include problems and activities aligned to the objective of the lesson that can be used for additional practice or to create your own problem set.

Next

Determine the impact of sample size on variability and prediction accuracy.

Lesson 5
icon/arrow/right/large

Lesson Map

A7CB09C2-D12F-4F55-80DB-37298FF0A765

Topic A: Understanding Populations and Samples

Topic B: Using Sample Data to Draw Inferences About a Population

Topic C: Using Sample Data to Compare Two or More Populations

Request a Demo

See all of the features of Fishtank in action and begin the conversation about adoption.

Learn more about Fishtank Learning School Adoption.

Contact Information

School Information

What courses are you interested in?

ELA

Math

Are you interested in onboarding professional learning for your teachers and instructional leaders?

Yes

No

Any other information you would like to provide about your school?

We Handle Materials So You Can Focus on Students

We Handle Materials So You Can Focus on Students

We've got you covered with rigorous, relevant, and adaptable math lesson plans for free