# SOLUTION: in a certain statistics class, the marks obtained by students on a class test followed a normal distribution with a mean of 68 and a standard deviation of 10. What is the probabili

Algebra ->  Algebra  -> Probability-and-statistics -> SOLUTION: in a certain statistics class, the marks obtained by students on a class test followed a normal distribution with a mean of 68 and a standard deviation of 10. What is the probabili      Log On

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 Algebra: Probability and statistics Solvers Lessons Answers archive Quiz In Depth

 Question 428037: in a certain statistics class, the marks obtained by students on a class test followed a normal distribution with a mean of 68 and a standard deviation of 10. What is the probability that the mean test mark from a sample of 25 students from the class was more than 70?Answer by stanbon(57962)   (Show Source): You can put this solution on YOUR website!in a certain statistics class, the marks obtained by students on a class test followed a normal distribution with a mean of 68 and a standard deviation of 10. What is the probability that the mean test mark from a sample of 25 students from the class was more than 70? --- t(70) = (70-68)/[10/sqrt(25)] = 1 --- P(x-bar > 70) = P(t > 1 when df = 24) = 0.1636 ===== Cheers, Stan H.