3.39 ● Consumer Reports Health (www.consumerreports.org)

gave the accompanying data on saturated fat (in grams), sodium (in mg), and calories for 36 fast-food items.

Fat Sodium Calories 2 1042 268 5 921 303 3 250 260 2 770 660 1 635 180 6 440 290 4.5 490 290 5 1160 360 3.5 970 300 1 1120 315 2 350 160 Fat Sodium Calories 3 450 200 6 800 320 3 1190 420 2 1090 120 5 570 290 3.5 1215 285 2.5 1160 390 0 520 140 2.5 1120 330 1 240 120 3 650 180 Fat Sodium Calories 1 1620 340 4 660 380 3 840 300 1.5 1050 490 3 1440 380 9 750 560 1 500 230 Fat Sodium Calories 1.5 1200 370 2.5 1200 330 3 1250 330 0 1040 220 0 760 260 2.5 780 220 3 500 230

a. Construct a scatterplot using y 5 calories and x 5 fat. Does it look like there is a relationship between fat and calories? Is the relationship what you expected? Explain.

b. Construct a scatterplot using y 5 calories and x 5 sodium. Write a few sentences commenting on the difference between the relationship of calories to fat and calories to sodium.

c. Construct a scatterplot using y 5 sodium and x 5 fat. Does there appear to be a relationship between fat and sodium?

d. Add a vertical line at x 5 3 and a horizontal line at y 5 900 to the scatterplot in Part (c). This divides the scatterplot into four regions, with some of the points in the scatterplot falling into each of the four regions. Which of the four regions corresponds to healthier fast-food choices? Explain.