The lifetime of a certain type of automobile tire (in thousands of miles) is normally distributed with a mean of 40 and a standard deviation of 6. Find the following probabilities, round to the fourth. (Round z-scores to two decimal places and probabilities to four places.) a) What is the probability 19 randomly chosen tires have an average lifetime greater than 40? P(x>40)=P(z>:])=:] Would it be unusual or usual for this to happen? 0 unusual O usual Shade: Left of a value v . Click and drag the arrows to adjust the values. b) What is the probability 14 randomly chosen tires have a lifetime less than 35? P(x