Reference no: EM132848718

Researchers interested in lead exposure due to car exhaust sampled the blood of 52 road construction workers subjected to constant inhalation of automobile exhaust fumes while working downtown in a city. The blood samples of these workers had an average lead concentration of 124.32 μg/l and a SD of 37.74 μg/l; a previous study of people from a nearby suburb, with no history of exposure, found an average blood level concentration of 35 μg/l.

a. What is the hypotheses that would be appropriate for testing if the construction workers appear to have been exposed to a higher concentration of lead.

b. Explicitly state and check all conditions necessary for inference on these data.

c. Test the hypothesis that the downtown construction workers have a higher lead exposure than the group in the previous study. Interpret your results in context.

d. Based on your preceding result, without performing a calculation, would a 99% confidence interval for the average blood concentration level of workers contain 35 μg/l?