My instructor comments on the statistics homework below “You mention

this indicates a moderate positive relationship which is true but HOW did you know this what about the value of r told you that?” “In statistics the word direct means positive is their a positive relationship between weight and MPG? ” I am not sure how to respond to this question. I pasted the section of my paper below. Can you please assist.

Predict the braking distance in feet for a car based on its weight in pounds
Linear Regression to determine the line-of-best fit:
·        What is the equation of the line-of-best fit?
Y= b0 + b1x
Y Intercept, b0:     125.30804
Slope, b1:           0.00319

·        What would you predict the braking distance would be for a car that weighs 2650 pounds?
Y= b0 + b1x
Y=  125.30804 + 0.00319 (2650)
Y= 125.30804 + 8.4535
Y= 133.7615
The braking distance is predicted at 133.7615 feet.
What would you predict braking distance would be for a muscle car that weighs 4250 pounds?
Y= b0+b1x
Y= 125.30804 + 0.00319 (4250)
Y= 125.30804 + 13.5575
Y= 138.8655
The braking distance is predicted at 138.8655
Calculate the coefficient of determination (R2 value) for this data. What does this tell you about the data?
Coeff of Det, R^2:    0.12343
R2 is how close the data are to the fitted regression line and shows the percent of the variable variation. 0% indicates that the model explains none of the variability of the response data around its mean and 100% indicates that it explains all of the variability.

The relation in this example, the r2=0.12343 shows only 12% of the variation from the best-fit line, this indicates that the model is a poor predictor of accuracy of braking distance related to the weight of the car.

NE