(a) The probability that the 10th transistor produced is the first with a defect is 0.02.
(b) The probability that the machine produces no defective transistors in a batch of 100 is 0.98^100, or 0.36.
(c) On average, you would expect to produce 50 transistors before the first with a defect. The standard deviation is 7.07.
(d) On average, you would expect to produce 20 transistors before the first with a defect. The standard deviation is 4.47.
(e) Increasing the probability of an event decreases the mean and increases the standard deviation of the wait time until success.
3.22 Defective rate. A machine that produces a special type of transistor (a component of
computers) has a 2% defective rate. The production is considered a random process where each
transistor is independent of the others.
(a) What is the probability that the 10th transistor produced is the first with a defect?
(b) What is the probability that the machine produces no defective transistors in a batch of 100?
(c) On average, how many transistors would you expect to be produced before the first with a
defect? What is the standard deviation?
(d) Another machine that also produces transistors has a 5% defective rate where each transistor
is produced independent of the others. On average how many transistors would you expect to
be produced with this machine before the first with a defect? What is the standard deviation?
(e) Based on your answers to parts (c) and (d), how does increasing the probability of an event
affect the mean and standard deviation of the wait time until success?
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1 answer