Exhibit 3-4 There Has Been a Recent Increase in the Popularity

Essay

Exhibit 3-4 There has been a recent increase in the popularity of caffeine-containing "energy drinks" or "functional beverages"--substances that are considered to be food that may provide some health benefit. However, caffeine in these drinks presents an important health concern, especially for women of childbearing age. Studies have shown an increased risk of spontaneous abortion and low birth weight children to women consuming more than 150 mg/day of caffeine. In a recent study, eighteen 12-oz servings of different brands of carbonated sodas were analyzed to ascertain their caffeine content, with the results presented below. The data are in mg/12-oz serving; if no caffeine was detected, this is reported as "* mg/serving."

-In the study referenced in Exhibit 3-4, the caffeine content of one popular brand of carbonated soda sold in fountain form at nine fast-food chains was also analyzed. The caffeine levels (expressed as mg / 12 oz serving) of the soda in fountain form are listed in the table below. ​ a) Construct a comparative (back to back) stem & leaf plot for the container vs. fountain amounts of caffeine. (Do not use the data for carbonated sodas where caffeine was not detected.) Describe how the two distributions compare. (b) What do you think might explain the differences between the two distributions?