SOLUTION: If light bulbs have lives that are normally distributed with a mean of 2500 hours and a standard deviation of 500 hours, approximately what percentage of light bulbs has a life of
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Question 1033184: If light bulbs have lives that are normally distributed with a mean of 2500 hours and a standard deviation of 500 hours, approximately what percentage of light bulbs has a life of more than 3000 hours?
A. About 84%
B. About 68%
C. About 32%
D. About 16% Answer by fractalier(6550) (Show Source):
You can put this solution on YOUR website! Since 68% (or so) values fall in between -1 sigma and +1 sigma, that leaves 32% that are outside...that means there are 16% more than 3000 and 16% less than 2000 hours...
Choice D.
