Chapter 2.3, Problem 37E

According to the article “Rubbing Hands Together Under Warm Air Dryers Can Counteract Bacteria Reduction” (Infectious Disease News, September 22, 2010) washing your hands isn’t enough—good “hand hygiene'' also includes drying hands thoroughly. The article described an experiment to compare bacteria reduction for three different hand-drying methods. In this experiment， subjects handled uncooked chicken for 45 seconds, then washed their hands with a single squirt of soap for 60 seconds, and then used one of the three hand-drying methods. After completely drying their hands, the bacteria count on their hands was measured.

Suppose you want to carry out a similar experiment and that you have 30 subjects who are willing to participate. Describe a method for randomly assigning each of the 30 subjects to one of the hand-drying methods. (Hint: See A Note on Random Assignment on page 50.)