Question: Elliptical trainers are becoming one of the more popular exercise machines. Their smooth and steady low-impact motion makes them a preferred choice for individuals with knee and ankle problems. But selecting the right trainer can be a difficult process. Price and quality are two important factors in any purchase decision. Are higher prices generally associated with higher quality elliptical trainers? Consumer Reports conducted extensive tests to develop an overall rating based on ease of use, ergonomics, construction, and exercise range. The following data show the price and rating for eight elliptical trainers tested.

Brand and Model Price ($) Rating

Precor 5.31 3700 87

Keys Fitness CG2 2500 84

Octane Fitness Q37e 2800 82

LifeFitness X1 Basic 1900 74

NordicTrack AudioStrider 990 1000 73

Schwinn 430 800 69

Vision Fitness X6100 1700 68

ProForm XP 520 Razor 600 55

a. Develop a scatter diagram with price as the independent variable.

b. An exercise equipment store that sells primarily higher priced equipment has a sign over the display area that says “Quality: You Get What You Pay For.” Based upon your analysis of the data for elliptical trainers, do you think this sign fairly reflects the price-quality relationship for elliptical trainers?

c. Use the least squares method to develop the estimated regression equation.

d. Use the estimated regression equation to predict the rating for an elliptical trainer with a price of $1500.