What a Point in a

Scatter Plot Means

Lesson 3

Let’s investigate points in scatter plots!

Today’s Goal

• I can describe the meaning of a point in a scatter plot in context.

The Giant Panda

Warm Up

A giant panda lives in a zoo. What does the point on the graph tell you about the panda?

“Giant Panda 2” by Sheila Lau via Wikimedia Commons. Public Domain.

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A giant panda lives in a zoo. What does the point on the graph tell you about the panda?

How did you know the meaning of each of the numbers?

What specific information did each axis give ou?

Weight and Fuel Efficiency

Activity 1

• MLR5: Co-Craft Questions and Problems

fuel efficiency

Fuel efficiency is a measure of the average distance a car will travel using a certain amount of gas.

Commonly this is measured in miles per gallon (mpg).

A car that has a fuel efficiency of 25 mpg should be able to drive approximately 25 miles while using a gallon of gas.

fuel efficiency

Many factors can influence fuel efficiency, including the way an engine is engineered, driving conditions, and what accessories are being used.

What would a scatter plot including these 2 variables look like?

Please begin working!

How did you find the automobile with the greatest weight?

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How did you find the automobile with the greatest fuel efficiency?

The data in this table is from automobiles that run on gasoline. Where do you think a hybrid car would appear?

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Did the scatter plot match your prediction?

Are you ready for more?

After a board game competition, the tournament director collects 50 dice from the games played and rolls each one until he gets bored and tries a different one. The scatter plot shows the number of times he rolled each die and the number of 6s that resulted during those rolls.

Select a point in the scatter �plot and give its approximate �coordinates, then tell the �story of that point in the �context of the problem.

Coat Sales

Activity 2

• MLR1: Stronger and Clearer Each Time
• Think Pair Share

A clothing store keep track of the average monthly temperature in degrees Celsius and coat sales in dollars.

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Predict what a scatter plot might look like when the temperature is along the x-axis and the sales of coats at a store is along the y-axis.

Begin working on your own. (5 min)

Discuss your thinking as a team.

(5 min)

• What does the point (15, 680) represent?
• For the month with the lowest average temperature, estimate the total amount made from coat sales.
• For the month with the smallest coat sales, estimate the average monthly temperature.

4. If there were a point at (0, A)� what would it represent?

5. What would a point at (B, 0)� represent?

6. Would it make sense to use� this trend to estimate the� value of sales when the � average monthly temperature� is 60^oC?

When discussing functions, what is a point of the form (0, A) called? What about (B, 0)?

In a scatter plot is there a y-intercept?

When the average monthly temperature goes up, what seems to be happening to sales?

What kind of information does a point in a scatter plot represent?

Two measurements for an individual in a population.

How do we know what info. is captured by a point in a scatter plot?

The axis labels tell us how to interpret the coordinates of the points.

Do trends in a scatter plot necessarily apply to individuals in the population?

No!

Today’s Goal

• I can describe the meaning of a point in a scatter plot in context.

Quarterbacks

Cool Down

Quarterback Rating

• A quarterback rating is a way of rating a quarterback in football on a scale of 0 to 158.3 based on many variables, like pass attempts, interceptions, and touchdown passes.
• A higher rating generally represents a quarterback with better passing statistics.

The data from this Cool Down refers to quarterbacks who were able to start in at least 16 games for their team in a season.