SOLUTION: A final exam in Math 160 has a mean of 73 with a standard deviation of 7.8. If 24 students are randomly selected, find the probability that the mean of their scores is greater than
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Question 1058428: A final exam in Math 160 has a mean of 73 with a standard deviation of 7.8. If 24 students are randomly selected, find the probability that the mean of their scores is greater than 78. Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! This is a t-test with t(df=23)
t=(x-mean)/s/sqrt(n)=(x-mean)*sqrt(24)/s
=(78-73)*sqrt(24)/7.8=3.14
That is the probability that t df=23 is >3.14.
From the table, t (0.995,23)=3.10
The probability or p-value here is <0.005 (it is 0.0046)
