Pollution: Carbon monoxide (CO) emissions for passenger cars has a mean of 9.4 g/mi. A company believes that its fleet of cars has CO emissions that differs from the national mean. They collect a random sample of 40 cars and find a mean of x = 8.9 with a standard deviation of 1.2. Assuming that the underlying distribution is relatively normal, at the 1% level of significance, does his sample provide evidence to support the company's claim