[EX03-043] Sports drinks are very popular in today’s culture around the world. The following table lists 10 different products you can buy in England and the values for three variables: cost per serving (in pence), energy per serving (in kilocalories), and carbohydrates per serving (in grams).

Sports Drink Cost Energy Carbs Lucozade Sport RTD 330ml pouch/can 72 92 21.1 Lucozade Sport RTD 500ml bot. 79 140 32 Lucozade Sport RTD 650ml sports bot. 119 182 41.6 POWERade 500ml bot. 119 120 30 Gatorade Sports 750ml 89 188 45 Science in Sport Go Electrolyte (500ml) 99 160 40 High Five Isotonic electrolyte (750ml) 99 220 55 Isostar powder (per litre) 5l tub 126 320 77 Isostar RTD 500ml bot. 99 150 35 Maxim Electrolyte (per litre) 2kg bag 66 296 75 Note: Cost is in pence (p), 0.01 of a British pound, worth $0.0187 on March 28, 2005 Energy is measured in kilocalories; carbs (carbohydrates) are measured in grams.

Source: http://www.simplyrunning.net/articles/sports_drinks.htm

a. Draw a scatter diagram using x  carbs/serving and y  energy/serving.

b. Does there appear to be a linear relationship?

c. Calculate the linear correlation coefficient, r.

d. What does this value of correlation seem to be telling us? Explain.

e. Repeat parts a through d using x  cost/serving and y  energy/serving. (Retain these solutions to use in Exercise 3.59, p. 185.)