Question: 22
(Choose 1 answer)
(See picture)
A. 0.61
B. 0.41
C. 0.31
D. 0.51
E. None of the other choices is correct
A student doing a summer internship in a com-
pany was asked to model the lifetime of cer-
tain equipment that the company makes. After
a series of tests, the student proposed that the
lifetime of the equipment can be modeled by
a random variable X that has the probability
density function
0
, x < 0
f(x) =
xe-r/10
100
What is the probability that the lifetime of the
equipment exceeds 20?
