Many people believe that there is a “Friday effect” in the stock market. They don’t necessarily spell out exactly what they mean by this, but there is a sense that stock prices tend to be lower on Fridays than on other days. Because stock prices are readily available on the Web, it should be fairly easy to test this (alternative) hypothesis empirically. Before collecting data and running a test, however, you must decide exactly which hypotheses you want to test because there are several possibilities. Formulate at least two sets of null/alternative hypotheses. Then gather some stock price data and test your hypotheses. Can you conclude that there is a statistically significant Friday effect in the stock market?