Write the letter of the response that best answers each problem.
Does the weight of a vehicle affect the gas mileage? The following random sample was collected where x = weight of a vehicle in hundreds of pounds and y = miles per gallon.
|
x (lb hundreds)
|
26
|
35
|
29
|
39
|
20
|
|
y(mpg)
|
22.0
|
16.1
|
18.8
|
15.7
|
23.4
|
1. Based on a scatter diagram, would you estimate the linear correlation coefficient to be:
(a) close to -1
(b) closer to 0 and negative
(c) close to 1
(d) closer to 0 and positive
(e) cannot determine
2. What is the equation for the least squares line?
(a) y = -32.55x + 0.448
(b) y = -32.55x - 0.448
(c) y = -32.55x + 0.448
(d) y = -0.448x + 32.55
(e) y = 0.448x - 32.55