Scores on the ACT college entrance exam are Normally distributed with a mean µ = 20 and standard deviation σ = 5. An SRS of 25 ACT scores is selected, construct a 95% Confidence Interval for the sample mean (X-Bar) and interpret your result.
statistics - PsyDAG, Tuesday, December 4, 2012 at 1:01pm
95% = mean ± 1.96 SEm
SEm = SD/√n
I'll let you do the calculations and interpretations.