Engineers define reliability as the probability that an item will perform its function under specific conditions for a specific period of time. A certain model airerat engine is designed so that each engine has probability 0.999 of performing properly for an hour of flight Company engineers test an SRS of 450 engines of this model. Let the number that operate for an hour without failure

a) Explain why X is a binomial tandem variable

b) Find the sean and standard deviation of X. Interpret each value in context

c) POX 40. Interpret this result

d) Two anglies failed the test. Are you convinced that this model of engine is less reliable than re supposed to be ComputePOX H) and use the result to justify your answer