a manufacturing company has 5 identical machines that produce nails. the probability that a machine will break down on any given day is .1. define a random variable x to be the number of machines that will break down in a day. a. what is the appropriate probability distribution for x? b. compute the probability that 4 machines will break down. c. compute the probability that at least 4 machines will break down. d. what is the expected number of machines that will break down in a day? e. what is the variance of the number of machines that will break down in a day?