Question: The pet-drug market is growing very rapidly. Before new pet drugs can be introduced into the market place, they must be approved by the FDA. In 1999, the Novartis Company was trying to get Anafranil, a drug to reduce dog anxiety, approved. According to an article (E. Tanouye, “The Ow in Bowwow: With Growing Market in Pet Drugs, Makers Revamp Clinical Trials,” The Wall Street Journal, April 13, 1999), Novartis had t find a way to translate a dog’s anxiety symptoms into numbers that could be used to prove to the FDA that the drug had a statistically significant effect on the condition.

a. What is meant by the phrase statistically significant effect?

b. Consider an experiment in which dogs suffering from anxiety are divided into two groups. One group will be given Anafranil, and the other will be given a placebo (that is, a drug without active ingredients). How can you translate a dog’s anxiety symptoms into numbers? In other words, define a continuous variable, X1, the measurement of effectiveness of the drug Anafranil, and X2, the measurement of the effectiveness of the placebo.

c. Building on your answer to part (b), define the null and alternative hypotheses for this study.