SOLUTION: What number of hours lie 2.5 standard deviations above and below the mean? If the distribution is unknown, determine the minimum percentage of lightbulbs with a life within 2.5 sta

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Question 1141293: What number of hours lie 2.5 standard deviations above and below the mean? If the distribution is unknown, determine the minimum percentage of lightbulbs with a life within 2.5 standard deviations of the mean

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
The probability in a normal distribution that something is >2.5 sd or <-2.5 sd is 0.0124
The minimum percentage within 2.5 sd s is 1- 1/(2.5)^2=1-0.16 or 0.84