JeantheBigone
Quite Involved in Discussions
I'm hoping some Covers can help me.
I'm studying for one of the ASQ exams and am stumped by a sample test question on reliability. This is not my area so maybe I'm missing the obvious.....
the question is:
A series system has three subsystems with the following distributions:
1) exponential life, MTBF=10,000 h
2) Weibull, theta = 12,000 hrs, beta = 0.42
3) exponential life, MTBF = 25,000 hrs
What is the reliability of the system at t=5000 hrs?
I get R(1) = 0.606, R(2) = 0.839, R(3) = 0.819,
so R(1)x R(2)x R(3) = 0.416, which is one of the answers.
The answer key however says that the correct answer is 0.249.
Can anyone help me see what I'm doing wrong?
I'm studying for one of the ASQ exams and am stumped by a sample test question on reliability. This is not my area so maybe I'm missing the obvious.....
the question is:
A series system has three subsystems with the following distributions:
1) exponential life, MTBF=10,000 h
2) Weibull, theta = 12,000 hrs, beta = 0.42
3) exponential life, MTBF = 25,000 hrs
What is the reliability of the system at t=5000 hrs?
I get R(1) = 0.606, R(2) = 0.839, R(3) = 0.819,
so R(1)x R(2)x R(3) = 0.416, which is one of the answers.
The answer key however says that the correct answer is 0.249.
Can anyone help me see what I'm doing wrong?