>Recently one of my students asked me to help with statistics. So, we work with Kaplan AP Statistics. There I see:
>"...decrease the margin of error by a factor of 1/4...."
>
>Just curious, is this passage completely understandable for those of you how was born in English language environment?

Maybe it's my lack of knowledge of statistics but........

At first I thought I knew what was meant but the more I looked at it the less clear it became.