Researchers interested in lead exposure due to car exhaust sampled the blood of 52 police officers subjected
Question:
Researchers interested in lead exposure due to car exhaust sampled the blood of 52 police officers subjected to constant inhalation of automobile exhaust fumes while working traffic enforcement in a primarily urban environment. The blood samples of these officers had an average lead concentration of 124.32 μg/l and an SD of 37.74 μg/l; a previous study of individuals from a nearby suburb, with no history of exposure, found an average blood level concentration of 35 μg/l.Write down the hypotheses that would be appropriate for testing if the police officers appear to have been exposed to a different concentration of lead. Assume all necessary conditions are satisfied for inference on these data. Test the hypothesis that the downtown police officers have a higher lead exposure than the group in the previous study. State the conclusion. (Since it’s a hypothesis test for a mean and the population standard deviation is unknown, you should conduct a t-test.)
Statistics The Exploration & Analysis of Data
ISBN: 978-1133164135
7th edition
Authors: Roxy Peck, Jay L. Devore