Listed below are measured amounts of lead in micrograms per

Listed below are measured amounts of lead (in micrograms per cubic meter, or g/m3)in the air. The EPA has established an air quality standard for lead of 1.5 g/m3.The measurements shown below were recorded at a building on different days. Use the given values to construct a 95% confidence interval estimate of the mean amount of lead in the air. Is there anything about this data set suggesting that the confidence interval might not be verygood?

What is the confidence interval for the population mean ?

________ g/m3 < < g/m3  _________ g/m3 (Round to three decimal places as needed.)

Is there anything about this data set suggesting that the confidence interval might not be very good?

A. Yes, because the sample mean is greater than 1.5 g/m3.

B. No, the data appears to be normally distributed.

C. Yes, because the confidence interval does not contain 1.5 g/m3.

D. Yes, the value of 5.40 appears to be an outlier.

Solution

confidence interval using t distribution:

-0.441 < u < 3.538

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D. Yes, the value of 5.40 appears to be an outlier.