Question: Records on a fleet of trucks reveal that the average life of a set of spark plugs is normally distributed with a population mean of 22,100 miles. A manufacturer of spark plugs claims that its plugs have an average life in excess of 22,100 miles. The fleet owner purchased 18 sets and found that the sample average life was 23,400 miles, the sample standard deviation was 1,500 miles and the calculated value of t = 3.677. Based on these findings, is there enough evidence to accept the manufacturer's claim at the 0.05 level. (Explain your answer)