An electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed, with mean equal to 800 hours and a standard deviation of 40 hours. A. Find the expected number of light bulbs which have a length of life between 680 to 720 hours if the firm manufactures 3000 light bulbs for the month. 65 94 102 78 B. Find the expected number of light bulbs which have a length of life between 800 to 840 hours if the firm manufactures 3000 light bulbs for the month. 358 1357 1024 874 C. Which of the following does not describe a characteristics of a normal probability distribution? The area under a normal curve is 1 or 10% There is perfect symmetry about the central value of the normal curve. The width of a normal curve is determined by the standard deviation. The normal curve is bell-shaped.
ASAP
An electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed, with mean equal to 800 hours and a standard deviation of 40 hours.
A. Find the expected number of light bulbs which have a length of life between 680 to 720 hours if the firm manufactures 3000 light bulbs for the month.
65
94
102
78
B.
Find the expected number of light bulbs which have a length of life between 800 to 840 hours if the firm manufactures 3000 light bulbs for the month.
358
1357
1024
874
C.
Which of the following does not describe a characteristics of a normal probability distribution?
The area under a normal curve is 1 or 10%
There is perfect symmetry about the central value of the normal curve.
The width of a normal curve is determined by the standard deviation.
The normal curve is bell-shaped.
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