Kizspy Question: 43
(Choose 1 answer)
The life of a semiconductor laser at a constant power is normally distributed with a mean of 7000 hours and a
standard deviation of 600 hours. What is the life in hours that 90% of the lasers exceed?
Let P(Z<1.28)=0.9.
A. 7540
B. 6460
C. 6232
D. 7768
E. None of the other choices is correct
