Published on April 18, 2016
1. The mean gas mileage for a hybrid car is 56 miles per gallon. Suppose that the gasoline mileage is approximately normally distributed with a standard deviation of 3.2 miles per gallon. 2. What conditions must n satisfy to make the x2 test valid? 3. To use the t-statistic to test for a difference between the means of two populations, what assumptions must be made about the two populations? About the two samples? 4. Studies of managers from two countries in the 1970s found sharp differences of opinion toward quality management. To find out if these differences continue to exist, researchers surveyed 100 managers in each country in the electronics manufacturing industry. The accompanying table gives the percentages of managers from each country who agree with each of 10 randomly selected statements regarding quality. Complete parts a through c. 5. Consider the horizandal box plot shown to the right. 6. A random sample of 100 observations from a population with standard deviation 58 yielded a sample mean 111. Complete parts a through c. 7. Graph the relative frequency histogram for the 300 measurements summarized in the relative frequency table to the right.