Using the exponential distribution, it is found that there is a 0.3297 = 32.97% probability that a randomly selected part will fail in less than 20 hours.
The exponential probability distribution, with mean m, is described by the following equation:
[tex]f(x) = \mu e^{-\mu x}[/tex]
In which [tex]\mu = \frac{1}{m}[/tex] is the decay parameter.
The probability that x is lower or equal to a is given by:
[tex]P(X \leq x) = \int\limits^a_0 {f(x)} \, dx[/tex]
Which has the following solution:
[tex]P(X \leq x) = 1 - e^{-\mu x}[/tex]
In this problem, the mean and the decay parameter are, respectively, given by:
[tex]m = 50, \mu = \frac{1}{50} = 0.02[/tex].
The probability that a randomly selected part will fail in less than 20 hours is given by:
[tex]P(X \leq 20) = 1 - e^{-0.02 \times 20} = 0.3297[/tex]
0.3297 = 32.97% probability that a randomly selected part will fail in less than 20 hours.
More can be learned about the exponential distribution at https://brainly.com/question/18596455
