'3-2-10 '1 2 3 '3 -2 -1 012 3 -3 -2 -1 0 1 One tail One tail Two tails Figure C.1: Three 15 distributions. one tail 0.100 0.050 0.025 0.010 0.005 (if 1 3.08 6.31 12.71 31.82 63.66 2 1.89 2.92 4.30 6.96 9.92 3 1.64 2.35 3.18 4.54 5.84 4 1.53 2.13 2.78 3.75 4.60 5 1.48 2.02 2.57 3.36 4.03 6 1.44 1.94 2.45 3.14 3.71 7 1.41 1.89 2.36 3.00 3.50 8 1.40 1.86 2.31 2.90 3.36 9 1.38 1.83 2.26 2.82 3.25 10 1.37 1.81 2.23 2.76 3.17 11 1.36 1.80 2.20 2.72 3.11 12 1.36 1.78 2.18 2.68 3.05 13 1.35 1.77 2.16 2.65 3.01 14 1.35 1.76 2.14 2.62 2.98 15 1.34 1.75 2.13 2.60 2.95 16 1.34 1.75 2.12 2.58 2.92 17 1.33 1.74 2.11 2.57 2.90 18 1.33 1.73 2.10 2.55 2.88 19 1.33 1.73 2.09 2.54 2.86 20 1.33 1.72 2.09 2.53 2.85 21 1.32 1.72 2.08 2.52 2.83 22 1.32 1.72 2.07 2.51 2.82 23 1.32 1.71 2.07 2.50 2.81 24 1.32 1.71 2.06 2.49 2.80 25 1.32 1.71 2.06 2.49 2.79 26 1.31 1.71 2.06 2.48 2.78 27 1.31 1.70 2.05 2.47 2.77 28 1.31 1.70 2.05 2.47 2.76 29 1.31 1.70 2.05 2.46 2.76 30 1.31 1.70 2 04 2 46 2.75 Condence level C 80% 90% 95% 98% 99% Question 1 1 pts Environmentalists, government ofcials, and vehicle manufacturers are all interested in studying the auto exhaust emissions produced by motor vehicles. The major pollutants in the auto exhaust from gasoline engines are hydrocarbons, monoxide, and nitrogen oxides (NOX). The following table gives the NOX levels (in grams per mile) for a random sample of 20 light-duty engines of the same type. I.\" We want to construct and interpret a 98% condence interval for the mean amount of NOX emitted by light-duty engines of this type. What is the parameter of interest V [Select] the mean amount of NOX emitted by the lightduty trucks in this sample the mean amount of NOX emitted by lightduty engines of this type. What is the condence level? [ Question 1 1 pt Environmentalists, government officials, and vehicle manufacturers are all interested in studying the auto exhaust emissions produced by motor vehicles. The major pollutants in the auto exhaust from gasoline engines are hydrocarbons, monoxide, and nitrogen oxides (NOX). The following table gives the NOX levels (in grams per mile) for a random sample of 20 light-duty engines of the same type. 1.28 1.17 1.16 1.08 0.60 0.95 2.20 1.78 1.83 1.26 1.31 1.45 1.22 1.32 1.47 2.27 1.87 1.94 1.16 1.45 We want to construct and interpret a 98% confidence interval for the mean amount of NOX emitted by light-duty engines of this type. What is the parameter of interest? [ Select ] What is the confidence level?