The VP for Sales at You Want It Motors wanted to determine i

The VP for Sales at You Want It Motors wanted to determine if there is a relationship between the vehicle\'s weight (1000 lbs) and fuel efficiency, in miles per gallon (MPG). A sample of 50 vehicles was collected from across the company and their fuel efficiency was measured over a set course that included both in city and highway driving. Based on the regression results shown below, What is the correlation between MPG and Weight?

The regression equation is MPG = 48.74 - 8.21 *Weight

R^2=0.7558 S=2.4134

A             -8.21

B             - 0.67

C             0.756

D             - 0.869

E              2.413

Answer is D, but I\'m really confused on how to calculate it.

Solution

Note that r = the correlation.

Here, we see that the slope is negative; hence, r is also negative.

Here,

r^2 = 0.7558

Getting the negative square root,

r = -0.869367586 [hence, it is OPTION D]