# 1000 Light Bulbs

by Subodh
(India)

1000 light bulbs with a mean life of 120 days are installed in a new factory and their length of life is normally distributed with a standard deviation of

30 days.

I need the answer & how to solve it.

Thanks'
&
regards

### Comments for 1000 Light Bulbs

Average Rating

 Rating ANSWER by: MATHS LEARNER` 1000 light bulbs with a mean life of 120 days are installed in a new factory and their length of life is normally distributed with a standard deviation of 30 days ANS : TAKE X PWR 1 =1000 MEU = 120 SD = 30 Z=120-1000/20

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