Hello all, I am trying to analyse some measurements at work. 29 samples were tested and I wanted to see what the confidence intervals are. I put everything into Excel and used the Excel functions to calculate the different values. (see picture) What I can't wrap my head around right now is why my confidence intervals are so tight. The range of the measurements is so much larger than the CI. According to the calculations 99,71% of the parts are gonna be between 64,999mm and 65,006mm. But 13 out of 29 samples are already outside of that range. That's almost 45%. How is this possible? Is there something I did wrong? Or is this caused by the small sample size? submitted by /u/Den5296 [link] [comments]