1. A candidate will stop spending money if she can be sure of winning. A poll of 150 voters showed 79 favored her. If alpha=0.05 can she stop spending?
2. Healthy 12 hour old infants average 7.5 pounds. A sample of 10 infants from a low income neighborhood gave xbar=7.08 and s=1.23. At alpha=0.01, do we have evidence that infants in this neighborhood are underweight? (What assumptions must be met to do this test?)
3. An assembly line is to be shut down for retooling if the variance of the product measurements is greater than 0.0057. If a sample of size 20 shows a sample variance of 0.0076, should the line be stopped? (What assumptions must be met to perform this test?)