Based on information from the Federal Highway Administration web site, the average annual miles driven per vehicle in the United States is 13.5 thousand miles. Assume ? ≈ 650 miles. Suppose that a random sample of 41 vehicles owned by residents of Chicago showed that the average mileage driven last year was 13.2 thousand miles. Would this indicate that the average miles driven per vehicle in Chicago is different from (higher or lower than) the national average? Use a 0.05 level of significance.   Sketch the sampling distribution and show the area corresponding to the P-value. (d) Based on your answers in parts (a) to (c), will you reject or fail to reject the null hypothesis? Are the data statistically significant at level ?? At the ? = 0.05 level, we reject the null hypothesis and conclude the data are statistically significant. At the ? = 0.05 level, we reject the null hypothesis and conclude the data are not statistically significant.    At the ? = 0.05 level, we fail to reject the null hypothesis and conclude the data are statistically significant. At the ? = 0.05 level, we fail to reject the null hypothesis and conclude the data are not statistically significant. (e) Interpret your conclusion in the context of the application. There is sufficient evidence at the 0.05 level to conclude that the miles driven per vehicle in the city differs from the national average. There is insufficient evidence at the 0.05 level to conclude that the miles driven per vehicle in the city differs from the national average.

In a city with three high schools, all the ninth graders took a Standardized Test, with these results: Number of ninth graders High School Mean score on test Glenwood 77 264 Central City Lincoln High 91 303 70 170 The city's PR manager, who never took statistics, claimed the mean score of all ninth graders in the city was 79.3. Of course, that is incorrect. What is the mean score for all ninth graders in the city? Round to one decimal place. mean of all ninth grader's scores =

The Grand Canyon and the Colorado River are beautiful, rugged, and sometimes dangerous. Assume there is a physician at the park clinic in Grand Canyon Village. Suppose the physician has recorded (for a 5-year period) the number of visitor injuries at different landing points for commercial boat trips down the Colorado River in both the Upper and Lower Grand Canyon. Compute a 5% trimmed mean for Upper Canyon and Lower Canyon. Round your answer to the nearest thousandth. Upper Canyon: Number of injuries per Landing Point Between North Canyon and Phantom Ranch 2 3 1 1 3 4 6 9 3 1 3 Lower Canyon: Number of injuries per Landing Point Between Bright Angel and Lava Falls 8 1 1 0 6 7 2 11 3 0 1 10 2 1 The 5% trimmed mean for Lower Canyon is 2.889 and for Upper Canyon is 3.500. The 5% trimmed mean for Lower Canyon is 2.364 and for Upper Canyon is 3.071. The 5% trimmed mean for Lower Canyon is 3.500 and for Upper Canyon is 2.889. The 5% trimmed mean for Lower Canyon is 3.000 and for Upper Canyon…

1. Consider a sample with data values of 2.20; 1.98; 1.95; 2.27; 2.25; 2,24; 2.31 Compute the mean.