A rods manufacturer makes rods with a length that is supposed to be 18 inches. A quality control technician sampled 22 rods and found that the sample mean length was 18.09 inches and the sample standard deviation was 0.22 inches. The technician claims that the mean rod length is more than 18 inches.

What type of hypothesis test should be performed?

What is the test statistic?

Does sufficient evidence exist at the =0.1 significance level to support the technician's claim? Yes or No