Introduction

Introduction

Stats Lab 12.1

Regression (Distance From School)

Class Time:

Names:

Student Learning Outcomes
  • The student will calculate and construct the line of best fit between two variables.
  • The student will evaluate the relationship between two variables to determine whether that relationship is significant.

Collect the DataUse eight members of your class for the sample. Collect bivariate data (distance an individual lives from school, the cost of supplies for the current term).

  1. Complete the table.
    Distance from School Cost of Supplies This Term
       
       
       
       
       
       
       
       
    Table 12.12
  2. Which variable should be the dependent variable and which should be the independent variable? Why?
  3. Graph distance vs. cost. Plot the points on the graph. Label both axes with words. Scale both axes.
    Blank graph with vertical and horizontal axes.
    Figure 12.20

Analyze the DataEnter your data into a calculator or computer. Write the linear equation, rounding to four decimal places.

  1. Calculate the following:
    1. a = ______
    2. b = ______
    3. correlation = ______
    4. n = ______
    5. equation: ŷ = ______
    6. Is the correlation significant? Why or why not? (Answer in one to three complete sentences.)
  2. Supply an answer for the following scenarios:
    1. For a person who lives eight miles from campus, predict the total cost of supplies this term.
    2. For a person who lives 80 miles from campus, predict the total cost of supplies this term.
  3. Obtain the graph on a calculator or computer. Sketch the regression line.
    Blank graph with vertical and horizontal axes.
    Figure 12.21
Discussion Questions
  1. Answer each question in complete sentences.
    1. Does the line seem to fit the data? Why?
    2. What does the correlation imply about the relationship between distance and cost?
  2. Are there any outliers? If so, which point is an outlier?
  3. Should the outlier, if it exists, be removed? Why or why not?