1) Use the given information below. What is the coefficient of correlation between miles per gallon and weight? What is the sign of the correlation coefficient? Does the coefficient of correlation indicate a strong correlation, weak correlation, or no correlation between the two variables? How do you know

MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
Publisher:Amos Gilat
Chapter1: Starting With Matlab
Section: Chapter Questions
Problem 1P
icon
Related questions
Question
100%

In this section, you will apply the statistical concepts and techniques covered in this week's reading about correlation coefficient and simple linear regression. A car rental company wants to evaluate the premise that heavier cars are less fuel efficient than lighter cars. In other words, the company expects that fuel efficiency (miles per gallon) and weight of the car (often measured in thousands of pounds) are correlated. Performing this analysis will help the company optimize its business model and charge its customers appropriately.

In this discussion, you will work with a cars data set that includes two variables:

Miles per gallon (coded as mpg in the data set)

Weight of the car (coded as wt in the data set)
  

The random sample was drawn from a CSV file. This data from the Python script is below and will help to answer questions about your unique sample data.

In your post, address the following questions using all the data provided:

 

Unnamed: 0

mpg

cyl

disp

hp

drat

wt

qsec

vs

am

gear

carb

18

Honda Civic

30.4

4

75.7

52

4.93

1.615

18.52

1

1

4

2

24

Pontiac Firebird

19.2

8

400.0

175

3.08

3.845

17.05

0

0

3

2

5

Valiant

18.1

6

225.0

105

2.76

3.460

20.22

1

0

3

1

6

Duster 360

14.3

8

360.0

245

3.21

3.570

15.84

0

0

3

4

13

Merc 450SLC

15.2

8

275.8

180

3.07

3.780

18.00

0

0

3

3

 

1) Use the given information below. What is the coefficient of correlation between miles per gallon and weight? What is the sign of the correlation coefficient? Does the coefficient of correlation indicate a strong correlation, weak correlation, or no correlation between the two variables? How do you know?

                mpg          wt

mpg  1.000000   -0.875315

wt     -0.875315   1.000000

 

2) Use the info below to write the simple linear regression equation for miles per gallon as the response variable and weight as the predictor variable. How might the car rental company use this model?

    OLS Regression Results: ==============================================================================

Dep. Variable: mpg                                  R-squared: 0.766

Model: OLS Adj.                                         R-squared: 0.758

Method: Least Squares                          F-statistic: 91.75

Date: Thu, 02 Feb 2023                          Prob (F-statistic): 2.47e-10

Time: 23:35:17                                           Log-Likelihood: -74.862

No. Observations: 30                              AIC: 153.7

Df Residuals: 28                                        BIC: 156.5

Df Model: 1                                                 Covariance Type: nonrobust ==============================================================================

                           coef          std err          t                   P>|t|          [0.025          0.975]

                         ------------------------------------------------------------------------------

Intercept     37.0899       1.878       19.750           0.000         33.243          40.937

wt                  -5.3404        0.558        -9.579            0.000         -6.482           -4.198 ==============================================================================

Omnibus:                         4.439                       Durbin-Watson:                  2.087

Prob(Omnibus):            0.109                     Jarque-Bera (JB):                 3.332

Skew:                                 0.812                            Prob(JB):                           0.189

Kurtosis:                           3.175                            Cond. No.                           12.3 ==============================================================================

 

3) Using the data provided in question 3, what is the slope coefficient? Is this coefficient significant at a 5% level of significance (alpha=0.05)? (Hint: Check the P-value, P>|t| , for weight in the Python output.)

Expert Solution
Step 1

Given that,

Dependent variable (y) = miles per gallon

Independent variable (x) = weight of the car

Level of significance (α) = 0.05

The correlation and regression output is given.

 

trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps

Blurred answer
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
MATLAB: An Introduction with Applications
MATLAB: An Introduction with Applications
Statistics
ISBN:
9781119256830
Author:
Amos Gilat
Publisher:
John Wiley & Sons Inc
Probability and Statistics for Engineering and th…
Probability and Statistics for Engineering and th…
Statistics
ISBN:
9781305251809
Author:
Jay L. Devore
Publisher:
Cengage Learning
Statistics for The Behavioral Sciences (MindTap C…
Statistics for The Behavioral Sciences (MindTap C…
Statistics
ISBN:
9781305504912
Author:
Frederick J Gravetter, Larry B. Wallnau
Publisher:
Cengage Learning
Elementary Statistics: Picturing the World (7th E…
Elementary Statistics: Picturing the World (7th E…
Statistics
ISBN:
9780134683416
Author:
Ron Larson, Betsy Farber
Publisher:
PEARSON
The Basic Practice of Statistics
The Basic Practice of Statistics
Statistics
ISBN:
9781319042578
Author:
David S. Moore, William I. Notz, Michael A. Fligner
Publisher:
W. H. Freeman
Introduction to the Practice of Statistics
Introduction to the Practice of Statistics
Statistics
ISBN:
9781319013387
Author:
David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:
W. H. Freeman