The makers of a soft drink want to identify the average age of its consumers. A sample of 16 consumers is taken. The average age in the sample was 22.5 years with a standard deviation of 5 years. Assume the population of consumer ages is normally distributed.
a. Using the confidence interval method, test the claim that the average age of consumers is at least 30 years (α= 0.05).
b. Test the same claim by using the test statistics method ( Z or T test).
c. Test the same claim by using the P-Value method ( Z or T test).