Link to download Jamovi: https://www.jamovi.org/download.html

In the previous question, researchers randomly collected data on motor vehicles from the United States of America. Another insight they are hoping to receive from the data is if there is a relationship between weight and the fuel economy of a vehicle.

The variables they are now interested in is are Weight which is measured in pounds (lb) and MPG Highway. The MPG variable is a measure of distance travelled per gallon of fuel used when driving on a highway.

The data appear in the file https://osf.io/t7brz/quickfiles.

(a)A scatterplot is a useful graphical tool for investigating possible relationships between two numerical variables. Produce a scatterplot using the data provided ensuring that you place the appropriate variables on the x-axis and y-axis. Describe the relationship between the two variables.

(b)Provide the equation for the linear regression model of highway MPG and weight. Interpret the numbers (b0 and b1) in the regression equation.

(c)Use the regression equation to predict the highway MPG of a vehicle with a weight of 3,000lb.

(d)How much of the variation in highway MPG is accounted for in the linear regression with weight as a predictor?

(e) Test at the 5% significance level if there is a relationship between critical highway MPG and weight. Be sure to include the following in your answer:

• the null and alternative hypotheses the test statistic
• the null distribution
• the p-value
• your conclusion

(f)Provide a 95% confidence interval for the population slope parameter and interpret this interval.

(g) List the assumptions of your analysis. To what degree are these assumptions satisfied? Include output from jamovi where appropriate.