SOLUTION: A large flashlight is powered by 5 batteries. Suppose that the life of a battery is normally distributed with mean 150 and standard deviation 15. The flashlight will cease function

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Question 1166036: A large flashlight is powered by 5 batteries. Suppose that the life of a battery is normally distributed with mean 150 and standard deviation 15. The flashlight will cease functioning if one or more of its batteries go dead. Assuming the lives of batteries are independent. What is the probability that flashlight will operate more than 130 hours?
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
So what is the probability all 5 batteries will last more than 130 hours?
the probability of one is z=(x-mean)/sd or z>(130-150)/15 or z> -1.33
this has probability of 0.9082
for all 5 batteries to do this would be 0.9082^5=0.6179.