Q2. Hypothesis Testing with a Z Test (12.5 points) According to the CDC report, the mean life expectancy in the US population is currently ([1) 78.5 years with a standard deviation (0) of 12. A researcher examined the age of death of 100 people recently recorded in several Arizona hospitals and calculated the mean to be 79.7 years old. He runs a two-tailed Z test with a = .05 to see if Arizona has a signicantly different life expectancy compared to the US population. Because the researcher is not predicting a direction, the hypotheses should be non- directional and the test should be two-tailed. a. What is the dependent variable in this research question? (.5 point)