SOLUTION: The average math SAT score is 516 with a standard deviation of 117. A particular high school claims that its students have unusually high math SAT scores. A random sample of 45 s

Question 635031: The average math SAT score is 516 with a standard deviation of 117. A particular high school claims that its students have unusually high math SAT scores. A random sample of 45 students from this school was selected, and the mean math score was 549. Is the high school justified in its claim? Explain.
Yes or No, because the z-score (??) is usual or unusual since it lies or does not lie within the range of a usual event, namely within 1, 2 or 3 deviation(s).
Please help answer the questions and find the z-score.
Answer by ewatrrr(24785) (Show Source): You can put this solution on YOUR website!

 

Hi,

average math SAT score is 516 with a standard deviation of 117.

Sample of 45 with mean math score of 549

z-score is easy enough.  One tailed test

 z = 

For a Sample group of size 45, generally an acceptable critcal area is z ≥ 1.68 (using One-tailed test)

That being the case, a z-score of 1.892 would be unusual as is 1.892 > 1.68 

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