posted by Andy .
The lifetime of computer chips is approximately normal with mean 1.4×106 hours and standard deviation 3×105 hours. The statistics department has 5 computers built with that chip as the main component. What is the probability that all 5 computers last longer than 1.8×106 hours?
Online "^" is used to indicate and exponent, e.g., x^2 = x squared.
Z = (score-mean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score.
If the events are independent, the probability of both/all events occurring is determined by multiplying the probabilities of the individual events.