Question: TWO DECIMAL ANSWERS: Listed below are measured amounts of carbon monoxide (in ppm over an 8 hour period) in the air. EPA has established an average air quality standard for carbon monoxide as 9 ppm over an 8 hour period. The measurements were recorded in downtown Oklahoma City on extremely busy driving days in January 2014.

a. Use the values below to construct a 95% confidence interval estimate of the mean amount of carbon monoxide in the air during all of January 2014.

9.45 10.67 10.45 8.45 7.60 7.40 8.60 6.75

b. Based on the confidence interval would you be concerned about the carbon monoxide levels in OKC? Why or why not?