suspect that the staff who work in circuses weigh less than the national average. When you think about it, that must be the case. They are always having to jump out of the way of lions, swing on trapezes and goodness only knows what else. And of course the audience expect the staff to be petite and trim. No beer-guts here, please! Fortunately I have some secretly obtained information. The global mean weight of circus staff is 56 kg, from a sample of 64. The standard deviation is 8 kg. What is the probability of finding a sample which weighs less than 55 kg? Round up to two decimal places.,.