4-2.5 In a class of 50 students, the result of a particularexamination is a true mean of 70 and a true variance of 12. It isdesired to estimate the mean by sampling, without replacement, asubset of the scores.
a) Find the standard deviation of the sample mean if only 10scores are used.
b) How large should the sample size be for the standarddeviation of the sample mean to be one percentage point (out of100)?
c) How large should the sample size be for the standarddeviation of the sample mean to be 1 % of the true mean?
I don't think need more informations in case this q from (Cooper- Probabilistic Methods of Signal and System Analysis, 3rd Ed) page185
