Chapter 14.2, Problem 5E

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 (Consumer Reports, February 2008).

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

1. a. Develop a scatter diagram with price as the independent variable.
2. 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 ellipical trainers, do you think this sign fairly reflects the price-quality relationship for elliptical trainers?
3. c. Use the least squares method to develop the estimated regression equation.
4. d. Use the estimated regression equation to predict the rating for an ellipitical trainer with a price of $1500.