ABC Manufacturing has 6 machines that perform a particular task. Breakdowns occu
ID: 2900842 • Letter: A
Question
ABC Manufacturing has 6 machines that perform a particular task. Breakdowns occur frequently for this machine. Past records indicate that the number of breakdowns that occur each day is described by the following probability distribution:
Number of Breakdowns Probability
0 0.4
1 0.3
2 0.2
3 0.1
More than 3 0.0
(a) What is the expected number of breakdowns in any given day?
(b) What is the variance for this distribution?
(c) What is the probability that there will be at least 2 breakdowns in a day?
Explanation / Answer
(a) expected value = 1.0
(b) variance = 1(.4) + 0(.3) + 1(.2) + 4(.1) = 1.0
(c) P(2 or more) = 0.2 + 0.1 = 0.3