SOLUTION: The lifetime of light bulbs that are advertised to last for 6200 hours are normally distributed with a mean of 6500 hours and a standard deviation of 150 hours. What is the probabi

Question 810265: The lifetime of light bulbs that are advertised to last for 6200 hours are normally distributed with a mean of 6500 hours and a standard deviation of 150 hours. What is the probability that a bulb lasts longer than the advertised figure?
Found 2 solutions by stanbon, taha:
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
The lifetime of light bulbs that are advertised to last for 6200 hours are normally distributed with a mean of 6500 hours and a standard deviation of 150 hours. What is the probability that a bulb lasts longer than the advertised figure?
-----------
z(6200) = (6200-6500)/150 = -2
-----
P(x > 6200) = P(z > -2) = normalcdf(-2,100) = 0.9772
=================
Cheers,
Stan H.
=============
Answer by taha(2) (Show Source): You can put this solution on YOUR website!
p(x>6200)=
p(z>(5200-6500)/150)=
-300/150=-2
p(z>-2)=
0.0.97

RELATED QUESTIONS
the lifetimes of a brand of electric light bulbs are normally distributed with mean... (answered by Boreal)
The lifetimes of a certain brand of light bulbs are known to be normally distributed with (answered by ewatrrr)
PLease help, I've posted multiple times but still haven't gotten an answer. A company... (answered by Theo)
The lifetimes of a certain brand of high intensity batteries are known to be normally... (answered by ewatrrr)
The lifetimes of light bulbs of a particular type are normally distributed with a mean of (answered by jim_thompson5910)
For a certain type of fluorescent light in a large building, the cost per bulb of... (answered by Boreal)
the lifetime of light bulbs of a particular type are normally distributed with a mean of... (answered by ewatrrr)
A manufacturer claims that the mean lifetime, , of its light bulbs is months. The... (answered by stanbon)
Light Bulbs have an advertised rating of 1750 lumens. If measurements are normally... (answered by ewatrrr)