A certain brand of automobile tire has a mean life span of 33,000 miles and a standard deviation of 2,100 miles. (Assume the life spans of the tires have a bell-shaped distribution.) (a) The life spans of three randomly selected tires are 34,000 miles, 37,000 miles, and 31,000 miles. Find the z-score that corresponds to each life span. For the life span of 34,000 miles, z-score is 0.48. (Round to the nearest hundredth as needed.) For the life span of 37,000 miles, z-score is 1.90 (Round to the nearest hundredth as needed.) For the life span of 31,000 miles, z-score is - 0.95 (Round to the nearest hundredth as needed.) According to the z-scores, would the life spans of any of these tires be considered unusual? x Yes No (b) The life spans of three randomly selected tires are 28,800 miles, 37,200 miles, and 33,000 miles. Using the empirical rule, find the percentile that corresponds to each life span. The life span 28,800 miles corresponds to a percentile of The life span 37,200 miles corresponds to a percentile of The life span 33,000 miles corresponds to a percentile of (Round to the nearest whole number as needed.)