Null and Alternative Hypotheses

  The manager of a department store disputes the company’s claim that the average age of consumers who buy a particular brand of clothes is 16. She believes the average age is older than 16. A clerk for the store stops the next 25 people buying these clothes and asks for their age. She calculates a mean age of 18.5 years, with a standard deviation of 2.25 years. Use the data from this sample to test the manager’s claim by answering the following: State the null and alternative hypotheses allowing the possibility that the average age may be younger than 16. Make a decision about the null hypothesis by identifying the following: Calculate the degrees of freedom Set alpha Identify the critical values State the decision rule