Math 7

Unit 7 Data Analysis

Lesson 7.3  The Effects of Outliers on Average

Focus

The FOCUS section introduces the main concept that will be covered in the lesson.

Understand how mean, median, and mode are affected by outliers.

There isn’t a Focus activity in this lesson.

Explore

Explore an idea or problem.
The exploration provides the background for the ideas presented in the lesson.

TEXT Page 267

Read/Work through the  Explore  section on Page 267 in your textbook.

You can do this activity on your own.
Do your best to answer the questions, then watch the Video Tutorial for help or to check your answers.

Watch

Video Tutorial

Connect

Connect summarizes the math in the lesson.
A presentation of ideas connected to the lesson focus.

TEXT Page 267

Read/Work through the  Connect  section on Page 267 in your textbook.

Bill Gates on the bus?   (optional, an example of outliers)

Made up example, but a great example of how the mean is affected by outliers

Ten people are riding on a bus in Redmond, Washington.

The mean income of those riders is $50,000 a year.

The median income of those riders is also $50,000 a year.

Joe Average gets off the bus.

Bill Gates gets on.  (ha... as if....)

The median income of those riders remains $50,000 a year.

But the mean income is now somewhere in the neighborhood of $50 million or so.

You could now correctly say that the average income of those bus riders is 50 million bucks.

But those other nine riders didn't become millionaires just because Bill Gates got on their bus.

A reporter who writes that the "average rider" on that bus earns $50,000 a year, using the median, provides a far more accurate picture of those bus riders' place in the economy.

Example

The Example will give you TOOLS for solving problems, and also show you that there may be different ways to approach a question.

Example

TEXT Page 268

Work through the Example  on Page 268 in your textbook.

Watch

Video Tutorial

Practice Problems

Doing Practice Problems

Practice problems reinforce the math presented in this lesson.

•	Work through the practice problems for this lesson.
	These problems are for practice, you don’t need to hand them in!
	(your teacher may assign specific questions for you to complete)

•	Use the answers in the back of the book to CHECK YOUR WORK!

•	If you make a mistake, TRY TO FIX IT!

•	If you need help or want more information, view the video solutions provided.

•	If you still need more help,  CONTACT YOUR TEACHER!

Types of Practice Problems

Assessment Focus a question that gives a good example of the kind of question you would be expected to answer after completing the lesson

Take It Further questions offer enrichment and extension.

Video Solution Links

Check your work for every problem you do!
If you make a mistake,  try to fix it!
Use the video solutions for more information.
If a problem still doesn’t make sense, ASK YOUR TEACHER FOR HELP!

({{"Question 1", "Question 2", "Question 3", "Question 4", "Question 5"}, {"Question 6", "Question 7", , , }})