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.