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