Statistics 1

If light bulbs are normally distributed with a mean of 2500 hrs. and a standard deviation of 500 hrs. what percentage of light bulbs have a life span less than 2500 hrs.?

asked by Tom gordy

  1. z = (score -mean)/sd
    z = (2500 -2500)/500
    z = 0 is 50%

    posted by Kuai
  2. 23

    posted by lana

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