The service time for customers at Stylum Barber Shop follows a normal distribution with a population standard deviation of 2 minutes. At the beginning of the fiscal year, the owner conducted a time study of 25 customers and discovered that the mean service time per customer was 12 minutes.  At the .05 confidence level, can it be concluded that the mean service time is less than 15 minutes?

Step 1.  State the Null Hypothesis and the Alternate Hypothesis

Step 2. Select a Level of Significance

Step 3. Select the Test Statistic

Step 4. Formulate the Decision Rule

Step 5. Make a Decision

Step 6. Interpret the Result