Probability and chance of failure

[Zach_C]

Ok, not really homework but I did not want to crowd general math.

I have an experiment that has 96% chance of working. If I try it one hundred times what is the chance of one being a failure.

I know with a one in two shot it is .5^2=.25 You now have a 25 percent chance of failure. Any help. Sorry at the moment my brain seems dead.

 

[Zach_C]

Oh my God I'm an idiot. I really am more tired than this thread let's on. :zzz:

 

[Hurkyl]

Try solving the opposite problem.

 

[xanthym]

Ok, not really homework but I did not want to crowd general math.

I have an experiment that has 96% chance of working. If I try it one hundred times what is the chance of one being a failure.

I know with a one in two shot it is .5^2=.25 You now have a 25 percent chance of failure. Any help. Sorry at the moment my brain seems dead.

Do you want the probability for "EXACTLY 1" Failure or for "AT LEAST 1" Failure?? Both can be determined from the Binomial Distribution:
Prob{Exactly 1 Failure} = (99)*{(0.96)^(99)}*{(1 - 0.96)^(1)} =
= (0.0696) = (6.96 %)
Prob{At Least 1 Failure} = 1 - Prob{Exactly 0 Failures} = 1 - (0.96)^100 =
= (0.983) = (98.3 %)


~~