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30. The diameter of ball bearings produced in a manufacturing process can be explained using a uniform distribution over the interval 3.5 to 5.5 millimeters. What is the mean diameter produced in this manufacturing process? a) 4.0 millimeters b) 4.5 millimeters c) 5.0 millimeters d) 5.5 millimeters e) 6.5 millimeters 31. Suppose x is a uniform random variable with c = 40 and d = 50. Find the standard deviation of x. a) 0= 8.333 b) = 14.434 C O= 2.887 d) o=.833 e o= 1.833 32. Transportation officials tells us that 60% of the population wear their seatbelts while driving. A random sample of 1000 drivers has been taken. Would you expect to see fewer than 100 with their seatbelt on? a) No, since the probability is .0188. b) Yes, since the probability is .0188. c) No, since the probability is .4812. d) Yes, since the probability is .4812