SOLUTION: The class average on a test was 81, with a standard deviation of 2.6. Find the probability that a student received at least a 78 on the test.

Question 823120: The class average on a test was 81, with a standard deviation of 2.6. Find the probability that a student received at least a 78 on the test.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
The class average on a test was 81, with a standard deviation of 2.6. Find the probability that a student received at least a 78 on the test.
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z(78) = (78-81)/2.6 = -3/2.6 = -1.1538
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P(x >= 78) = P(z >= -1.1538) = normalcdf(-1.1538,100) = 0.8757
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Cheers,
Stan H.
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