Question

6. Benzene in the air workers breathe can cause cancer. It is very important for the benzene content of air in a particular plant to be not more than 1.00 ppm. Benzene contents in this case are found to be normally distributed with a population standard deviation of 0.45 ppm. Samples are taken to check the benzene content of the air. 38 specimens of air from one location in the plant gave a mean content of 0.89 ppm. Directions • Perform a hypothesis test to determine if there is evidence, at the 4% level of signi- ficance, that the true mean benzene content is less than 1.00 ppm. Use the critical region method to make your decision. • State your hypotheses. • Calculate your test statistic (up to 2 decimals). • State the critical region. • State your decision (Reject or Not Reject H 0 ). • State your conclusion.

Answer 1