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Test scores on an exam follow a normal distribution with mean = 72 and standard deviation...

Test scores on an exam follow a normal distribution with mean = 72 and standard deviation = 9.  For a randomly selected student, find

           a) P(x ≥ 80), b) P(65 <x<90), what is thed minimum svore to be among top 12 percent

Math   Statistics-And-Probability   
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