- Load the cars dataset into R. It is a built-in dataset.
- Do an str() to determine the number of observations and variables. Enter your answer as a comment.
- Plot speed on x axis and distance on y axis.
- Find the correlation between speed and distance. What does the magnitude and sign indicate? Enter your answer as a comment.
- Build a linear regression model with speed as the independent variable and distance as the dependent variable (all raised to first power).
- Write the regression equation from question 5 as a comment.
- Interpret the intercept and slope coefficients from question 6 in your own words as a comment.
- What is the R square value of the regression model from question 5? What is the definition of R square value in the context of this question? Write your answer as a comment.
- Are the coefficients significant at 0.001 level of significance for the regression model from question 5? How do you determine that? Enter your answer as a comment.
- What is the distance value for a speed of 25 units using the regression equation from question 6? You can calculate it by hand. Enter your answer as a comment.
Sample Solution
