how do i calculate confidence intervals in MS excel ?

Question

I have 4 groups of numbers for a quality score - calculating the mean score is easy enough but I need 95% confidence intervals, I know there is a NORMINV function that can be used for this purpose ... how do I use this function to calculate what I need ? Is there any other way of doing it ?

Answer 1

This link should take you through what you need to do. Good luck!
http://www.cvgs.k12.va.us/DIGSTATS/main/Guides/g_ConfidenceExcel.htm

Answer 2

You can compute the standard error (sterr in Excel); the confidence interval is +/-( s.e.)*1.96