For each given situation, determine if the method of randomization is either appropriate or not appropriate. A laboratory wants to know how having chicken pox as a child has affected people's immune systems as adults. They randomize the study by assigning subjects to groups based on a random drawing. A university wants to test the health effects of a certain sweetener. Prior to testing the sweetener, they randomize the experiment by flipping a fair coin that assigns each person to the experimental or control group. A car company is performing a survey to find out about people's driving habits in a certain city. They randomize the survey by talking to every 50th person who leaves a movie theater within this certain city.