Acertain brand of auto mobile tire has a mean life span of 39,000 miles and a standard deviation of 2,300 miles. (Assume the life spans of the tires have a bellshaped distn'bution.) (a) The life spans of three randomly selected tires are 34,000 miles, 33,000 miles, and 32,000 miles. Find the zscore that corresponds to each liie span. For the life span of 34,000 miles, zscore is . (Round to the nearest hundredth as needed.)