4.2 The article “Caffeinated Energy Drinks—A Growing Problem” (Drug and Alcohol Dependence [2009]: 1–10)

gave the following data on caffeine concentration

(mg/ounce) for eight top-selling energy drinks:

Energy Drink Caffeine Concentration

(mg/oz)

Red Bull 9.6 Monster 10.0 Rockstar 10.0 Full Throttle 9.0 No Fear 10.9 Amp 8.9 SoBe Adrenaline Rush 9.5 Tab Energy 9.1

a. What is the value of the mean caffeine concentration for this set of top-selling energy drinks?

b. Coca-Cola has 2.9 mg/ounce of caffeine and Pepsi Cola has 3.2 mg/ounce of caffeine.

Write a sentence explaining how the caffeine concentration of top-selling energy drinks compares to that of these colas.