Harry_the_cat
Elite Member
- Joined
- Mar 16, 2016
- Messages
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If you have 3 independent pieces of equipment, each with the same average time between failures and same std dev. What is the mean time and std dev between any failure?
For example, if X=X1=X2=X3, and sd=sd1=sd2=sd3
I would say, intuitively, that mean time between any failure is 31X. I want to say that std dev is 31sd but I'm not convinced.
Any help appreciated.
And then I need to consider what if the means and std devs are not equal.
For example, if X=X1=X2=X3, and sd=sd1=sd2=sd3
I would say, intuitively, that mean time between any failure is 31X. I want to say that std dev is 31sd but I'm not convinced.
Any help appreciated.
And then I need to consider what if the means and std devs are not equal.