Please Explain Why, Will Leave Thumbs Up. The lifetime of a semiconductor laser
ID: 3363361 • Letter: P
Question
Please Explain Why, Will Leave Thumbs Up.
The lifetime of a semiconductor laser has a lognormal distribution, and it is known that the mean and standard deviation of lifetime are 10,000 and 20,000, respectively. What is the probability that the lifetime of a randomly selected semiconductor will exceed 10,000 hours? a. Binomial b. Negative Binomial c. Hypergeometric d. Poisson e. Normal f. Exponential g. Lognormal The life of a semiconductor laser at a constant power is normally distributed with a mean of 7000 hours and a standard deviation of 600 hours. What is the probability that the laser fails before 5000 hours? a. Binomial b. Negative Binomial c. Hypergeometric d. Poisson e. Normal f. Exponential g. Lognormal The number of flaws in bolts of cloth in textile manufacturing is assumed to be Poisson distributed with a mean of 0.1 flaw per square meter. What is the probability that here are two flaws in 1 square meter of cloth? a. Binomial b. Negative Binomial c. Hypergeometric d. Poisson e. Normal f. Exponential g. LognormalExplanation / Answer
Solution:-
a) Lognormal distribution.
In probability theory, a log-normal (or lognormal) distribution is a continuous probability distribution of a random variable whose logarithm is normally distributed.
In this example lifetime of semiconductor is lognormally distributed hence, lifetime of selected semiconductor will follows Lognormal distribution.
b) Normal distribution.
In this example power of semiconductor is normally distributed hence, power of selected semiconductor will follows normal distribution.
c) Poisons distribution.
In this example flaws per square meter follows poisons distribution hence, probability of two flaws in 1 square meter is also given by poisons distribution.