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The compressive strength of samples of cement can be modeled by a normal distribution with a...

The compressive strength of samples of cement can be modeled by a normal distribution with a mean of 9000 Kg/cm2 and a standard deviation of 200 Kg/cm2.

  1. What is the probability that a sample’s strength is less than 8250 Kg/cm2.
  2. What is the probability that a sample’s strength is between 4800 and 6800 Kg/cm2.
  3. What strength is exceeded by 87.78% the samples?
Math   Statistics-And-Probability   
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