1. Lesson 2

1.6. Explore 2

Mathematics 30-2 Module 4

Module 4: Polynomials

 

In Try This 2, you used your calculator to determine a linear regression. If you graphed the regression equation along with the data points, it would have looked like the following.

 

This diagram shows a scatter plot with the linear regression equation y equals 0.23 x minus 18.30.

A regression equation can be treated like a line of best fit.

 

A height of 160 cm was within the domain of the given data. Using a regression equation for an x-value in the domain of the data is called interpolation.

 

A height of 140 cm was not within the domain of the given data. Using a regression equation for an x-value not in the domain of the data is called extrapolation.

 

This diagram shows that a prediction made using a regression equation outside of the data set is an extrapolation and a prediction made using a regression equation within the data set is an interpolation.

Predicting the hand span of a person who is 140 cm is an extrapolation, because 140 cm is outside the data set. Predicting the hand span of a person who is 160 cm is an interpolation, because
160 cm is within the data set.



textbook

Read “Example 1” on pages 296 to 299 of your textbook. In this example, linear model is referring to a linear regression equation. Pay particular attention to the following differences in Carmen’s and Sandra’s solutions:

  • values for x (representing year) used to create the equations
  • method used for estimating a possible world-record distance for 2006
Self-Check 1

 

Complete questions 1, 2, and 4 on pages 301 and 302 of your textbook. Answers