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 probabil
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Question 1182136: 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 72? Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! this is a z-test
z=(x bar-mean)/sigma/sqrt(n)
>)72-68)/10/sqrt(25)
>20/10
>2
probability is 0.0228
