Large Marge's Trucking Company claims that the average weight of its delivery trucks when they are fully loaded is 5,500 pounds, and the standard deviation is 210 pounds. Assume that the population follows a normal distribution. Forty trucks are randomly selected and weighed. a) What is the probability that the sample average weight of 40 fully-loaded delivery trucks is more than 5530 pounds? (Round answer to four decimal places.) b) Within what limits will 91% of the sample average weights occur? to (Round answers to three decimal places.) c) What is the probability that the weight of a randomly selected fully-loaded delivery truck is between 5400 and 5550 pounds? (Round answer to four decimal places.)