A pipes manufacturer makes pipes with a length that is supposed to be 13 inches. A quality control technician sampled 25 pipes and found that the sample mean length was 13.04 inches and the sample standard deviation was 0.14 inches. The technician claims that the mean pipe length is not 13 inches. 1. What type of hypothesis test should be performed? What is the test statistic?

2. What is the number of degrees of freedom?

3. Does sufficient evidence exist at the a= 0.1 significance level to support the technician's claim?