Question

1. A researcher claims that the mean age of women in California at the time of a first marriage is higher than 26.5 years. Surveying a simple random sample of 210 newlywed women in California, the researcher found a mean age of 27.0 years. Assuming that the population standard deviation is 2.3 years and using a 95% level of confidence, determine if there is sufficient evidence to support the researcher’s claim.

2. Nurses in a large teaching hospital have complained for many years that they are overworked and understaffed. The consensus among the nursing staff is that the mean number of patients per nurse each shift is at least 8.0. The hospital administrators claim that the mean is lower than 8.0. In order to prove their point to the nursing staff, the administrators gather information from a simple random sample of 18 nurses’ shifts. The sample mean is 7.5 patients per nurse with a standard deviation of 1.1 patients per nurse.

Answer 1