In: Statistics and Probability
1. If you decrease the level of confidence from 99% to 95%, the width of confidence interval will A. increase by 4% B. decrease by 4% C. decrease by 8% D. None of the above
2. If you wish to decrease the margin of error, you may do which one of the following: A. Increase the sample size. B. Reduce the population size. C. Decrease the level of confidence.
D. Both b and c E. Both a and c
3. In five test runs, a truck operated 10, 12, 10, 8, and 15 miles with one gallon of gasoline. At the 98% level of confidence, is this sufficient evidence to show that the truck is operating at a mean rate of about 14 miles per gallon? A. Yes. B. No. C. Can’t be determined. D. Depends on the proportion of the tested truck