Question 609896
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Hi, re TY, see higlighted Percentage (Others were for comparison purposes only)
the lifetime of light bulbs of a particular type are normally distributed with a mean of 370 hours and a standard deviation of 5 hours. 
What percentage of bulbs has life times that lie within 1 standard deviation of the mean on either side? 
****one  standard deviation from the mean accounts for about {{{highlight(68.2)}}}% of the set 

two standard deviations from the mean account for about 95.4%
and three standard deviations from the mean account for about 99.7%.
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