SOLUTION: A) What is the 90% confidence interval for the variance of exam scores for 28 algebra students, if the standard deviation of their last exam was 12.7? B)A lawyer researched the

Question 172989: A) What is the 90% confidence interval for the variance of exam scores for 28 algebra students, if the standard deviation of their last exam was 12.7?
B)A lawyer researched the average number of years served by 49 different justices on the Supreme Court. The average number of years served was 14.9 years with a standard deviation of 8.6 years. What is the 95% confidence interval for the average number of years served by all Supreme Court justices?
C)A high school math teacher thinks the variance on his next math test should be 125. When his class of 27 students takes the next test, they have a standard deviation of 133. The test value for this data would be 27.664.

Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Do you still need help with these problems?
I see they were posted a week ago.
Cheers,
Stan H.
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