Chapter 14.2, Problem 9E

Using a global-positioning-system (GPS)-based navigator for your car, you enter a destination and the system will plot a route, give spoken turn-by-turn directions, and show your progress along the route. Today, even budget units include features previously available only on more expensive models. Consumer Reports conducted extensive tests of GPS-based navigators and developed an overall rating based on factors such as ease of use, driver information, display, and battery life. The following data show the price and rating for a sample of 20 GPS units with a 4.3-inch screen that Consumer Reports tested (Consumer Reports website, April 17, 2012).

Brand and Model	Price ($)	Rating
Garmin Nuvi 3490LMT	400	82
Garmin Nuvi 3450	330	80
Garmin Nuvi 3790T	350	77
Garmin Nuvi 3790LMT	400	77
Garmin Nuvi 3750	250	74
Garmin Nuvi 2475LT	230	74
Garmin Nuvi 2455LT	160	73
Garmin Nuvi 2370LT	270	71
Garmin Nuvi 2360LT	250	71
Garmin Nuvi 2360LMT	220	71
Garmin Nuvi 755T	260	70
Motorola Motonab TN565t	200	68
Motorola Motonab TN555	200	67
Garmin Nuvi 1350T	150	65
Garmin Nuvi 1350LMT	180	65
Garmin Nuvi 2300	160	65
Garmin Nuvi 1350	130	64
Tom Tom VIA 1435T	200	62
Garmin Nuvi 1300	140	62
Garmin Nuvi 1300LM	180	62

1. a. Develop a scatter diagram with price as the independent variable.
2. b. What does the scatter diagram developed in part (a) indicate about the relationship between the two variables?
3. c. Use the least squares method to develop the estimated regression equation.
4. d. Predict the rating for a GPS system with a 4.3-inch screen that has a price of $200.