A certain brand of automobile tire has a mean life span of 34,000 miles and a standard deviation of 2,250 miles. (Assume the life spans of the tires have a bell-shaped distribution.) (a) The life spans of three randomly selected tires are 35,000 miles, 38,000 miles, and 31,000 miles. Find the z-score that corresponds to each life span. For the life span of 35,000 miles, z-score is (Round to the nearest hundredth as needed.) For the life span of 38,000 miles, z-score is (Round to the nearest hundredth as needed.) For the life span of 31,000 miles, z-score is (Round to the nearest hundredth as needed.) According to the z-scores, would the life spans of any of these tires be considered unusual? O Yes O No