An engineer believes that W, the weight that a structure can support without structural damage, has a normal distributio

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An engineer believes that W, the weight that a structure can
support without structural damage, has a normal distribution with
mean 300000 kg and standard deviation 10000 kg. has a normal
distribution with mean 300000 kg and standard deviation 10000 kg.
If cars pass by with a weight that has an expected value of 900 kg
with standard deviation 200 kg, how many cars must be on the bridge
for structural damage to occur? Calculate the number of cars
for different probabilities of structural damage
(0.1,0.25,0.5,0.75,0.99).