Normal distribution and percentage of light bulbs

Reference no: EM13102875

If light bulbs have lives that are normally distributed with a mean of 2500 hours and a standard deviation of 500 hours, what percentage of light bulbs have a life less than 2500 hours? I know the answer is 50% but once you determine the z=0 how do you show you got to .50 or 50%?

Reference no: EM13102875

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