A factory produces car tires. The number of miles each tire lasts before it completely wares out follows a normal distribution with mean u 50,000 miles and standard deviation a = 8,000 miles. Suppose that the factory promises to the consumers that the tires will last for at least 62,000 miles. What is the probability for a randomly selected tire to last for at least 62,000 miles, i.e., P(x 2 62,000)