A group students take a Statistics Exam where the average was M = 77 and the...

A group students take a Statistics Exam where the average was M = 77 and the standard deviation was SD=4. If a student scored a 70 on the exam, what percentage of students scored ABOVE her?

Expert Solution

Data given:
Mean = 77, SD = 4, P(Y > 70) = ?;

P(Y > 70) = P(Y - mean > 70 - mean)
                  = P( (Y - mean)/SD > (70 - mean)/SD
                  = P(Z > (70 - mean)/SD)
                  = P(Z > (70 - 77)/4)
                  = P(Z > -1.75)
                  = 1 - P(Z <= -1.75)
                  = 0.96----------------from normal distribution table.

Approximately 96% students scored above her.

orchestra answered 1 year ago

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