According to the Centers for Disease Control and Prevention, average life expectancy in the United States has risen to 77.6 years (source: cnn.com). It has been suggested that residents in rural areas of the Southwest have a shorter life span than the general population. In a random sample of 250 recently deceased residents of the rural Southwest, the average life span was 75.9 years with a sample standard deviation of 9.8 years. Is the sample evidence sufficient to reject the null hypothesis shown below? Use a significance level of .05. H0: μ > 77.6 (The average life expectancy for residents of the rural Southwest is at least as long as the national average.) Ha: μ < 77.6 (The average life expectancy for residents of the rural Southwest is shorter than the national average.)