The amounts of nicotine in a certain brand of cigarette are normally distributed with a mean of 8.6 mg and a standard deviation of 1.57 mg. The company that produces these cigarettes claims that it has now reduced the amount of nicotine. The supporting evidence consists of a sample of 31 cigarettes with a mean nicotine amount of 8.008 mg. Assuming that the given mean and standard deviation have NOT changed, find the probability of randomly seleting 31 cigarettes with a mean of 8.008 mg or less. P(M < 8.008 mg) =