RE.1 Predictions Making Sense of Models

Name: Teacher: Date: Period:

Regression Equations Learning Targets
S-IDc: I can interpret linear models.
S-IDb: I can summarize, represent and interpret data on two categorical and quantitative variables.

My Right Foot

Mr. Harmson’s class measured the height of each student and length of their right foot.

He used technology to draw the linear regression equation that fits the data.

1.  What two variables are being compared in the scatter plot?

2.  Which variable is the independent variable?

3.  Use the scatter plot to predict the length of a student’s right shoe if they are 72 inches tall.

4.  Use the scatter plot to predict the height of a student with a 7 inch right foot.

The regression equation of the line is f(x) = 0.5x - 24

5. Jason says the slope means that the length of your right foot is on average half your

height. Explain why you agree or disagree with Jason.


The Cost of Diamonds

The data comes from a newspaper advertisement.[1].

6.  What two variables are being compared in the scatter plot?

7.  Which variable is the independent variable?

8.  Use the scatter plot to predict the cost of a 0.25-carat diamond.

9.  Use the scatter plot to predict the weight of a diamond that costs $800.

The regression equation is f(x) = 3721x – 257

10. Write a sentence to explain what the slope means in the context of the situation.

2009 Swine Flu Pandemic

The last large Swine Flu pandemic was in 2009. The first case of Swine Flu reported that year was on April 26, 2009[2].

The following scatter plot shows how many cases were reported each day in the World.

11. What two variables are being compared in the scatter plot?

12. Which variable is the dependent variable?

13. Use the scatter plot to predict the first day that there are more than 15,000 cases.

14. Use the scatter plot to predict the number of cases two weeks after the initial outbreak.

The regression equation is

15. Write a sentence to explain what the growth rate is and what it means in the context of the

situation.

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[1] http://www.statcrunch.com/5.0/shareddata.php?keywords=exponential+&Submit=Search&startlimit=0

[2] This data was collected daily from the CDC, http://www.cdc.gov/, at the time of the pandemic.