Suppose a tire manufacturer states the average lifetime of t…
Suppose a tire manufacturer states the average lifetime of their tires is 70,000 miles, with a standard deviation of 1,500 miles. Consider a random sample of 38 tires from this manufacturer. (Round to 3 decimal places.) a. Find the standard deviation of the sample mean. b. Find the probability that the sample mean is greater than 69,500 miles.