Homework Help: math

Posted by Bridget on Monday, April 2, 2012 at 6:10pm.

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?

math - PsyDAG, Tuesday, April 3, 2012 at 12:15pm
Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the Z score.
math - PsyDAG, Tuesday, April 3, 2012 at 12:15pm
Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the Z score.

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