The weight of trucks traveling on a particular section of 1475 has a population mean of 15.8 tons and a population standard deviation of 4.2 tons. What is the probability a state highway inspector could select a sample of 51 trucks and find the sample mean to be 14.3 tons or less? 0.0054 0.3624 0.1376 0.4946 The Office of Student Services at a large western state university maintains information on the study habits of its full-time students. Their studies indicate that the mean amount of time undergraduate students study per week is 20 hours. The hours studied follows the normal distribution with a population standard deviation of six hours. Suppose we select a random sample of 100 current students. What is the probability that the mean of this sample is between 19.25 hours and 21.0 hours? 0.9050 0.0548 0.1374 0.8469