Default value of a. If a is not given, use .05. A random sample from a certain population consists of the following 5 observations: 12, 10, 18, 18, 17. Test the claim that the population mean is less...

Extracted text: Default value of a. If a is not given, use .05. A random sample from a certain population consists of the following 5 observations: 12, 10, 18, 18, 17. Test the claim that the population mean is less than 19, and give the 5 elements of the test. Assume normality if necessary.