What is the appropriate sample size for a confidence interval around the sample mean if you want a margin of error of 0.8 with 95% confidence and a population standard deviation of 12.
Statistics - PsyDAG, Saturday, December 1, 2012 at 1:35pm
95% = mean ± 1.96 SEm
SEm = SD/√n
.8 = 1.96 (12/√n)
Solve for n.