Question

Listed below are measured amounts of lead in the air. The EPA has established an air quality standard for lead of 1.5 μg/m3. The measurements shown below were recorded at Building 5 of the World Trade Center site on different days immediately following the attacks of Sep. 11. Use a 0.05 significance level to test the claim that the sample is from a population with a mean greater than the EPA standard. Is there anything about this data set suggesting the assumption of a normally distributed population might not be valid?

5.40 1.10 0.42 0.73 0.48 1.10

Answer 1