11-6: Additional Problem Solving

Part 1

Example Comparing Trend Lines With and Without Outliers

The table and scatter plot show the length of certain models of cars and the miles per gallon they average when driven in the city. The scatter plot suggests a linear association.

A scatter plot: Car Length and MPG. x-axis: length (inches). y-axis: city (mpg). Points: 25 plotted from 183 to 215 on the x-axis and from 17 to 24 on the y-axis with a negative linear association, an oval-shaped cluster centered at (192, 20), and outliers at (212, 17) and (215, 17).

  • a. Draw a trend line and find its equation.

  • b. Remove the outliers, (212, 17) and (215, 17), from the table. Draw a new trend line for the adjusted data set. Then find the equation for this trend line.

  • c. How do the outliers affect the position of a trend line? Explain your reasoning by examining the slope of each line.

End ofPage 393

Table of Contents

Digits, Grade 8, Volume 2, Homework Helper Unit D: Two-Dimensional Shapes Unit E: Measurement and Data Unit F: Personal Financial Literacy Unit G: Step-Up Lessons English/Spanish Glossary Formulas Math Symbols Formulas Measures Properties