SOLUTION: A market researcher wants to find a confidence interval estimate of the mean age of all TCC students. A study done earlier in the year found that the standard deviation of all TCC

Algebra ->  Probability-and-statistics -> SOLUTION: A market researcher wants to find a confidence interval estimate of the mean age of all TCC students. A study done earlier in the year found that the standard deviation of all TCC       Log On


   



Question 437886: A market researcher wants to find a confidence interval estimate of the mean age of all TCC students. A study done earlier in the year found that the standard deviation of all TCC student ages was 14.2 years. How large a random sample must the researcher take in order to be 95% confident that the margin of error is 3.2 years?

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
A market researcher wants to find a confidence interval estimate of the mean age of all TCC students. A study done earlier in the year found that the standard deviation of all TCC student ages was 14.2 years. How large a random sample must the researcher take in order to be 95% confident that the margin of error is 3.2 years?
----
Since E = zs/sqrt(n)
n = [zs/E]^2
----
n = [1.96*14.2/3.2]^2 = 76 when rounded up
Cheers,
Stan H.