<p>Sometimes students in statistics courses are taught to report means with one more digit of significance than the original measure. For example, if the reported values were 8.2, 9.7, 10.4, one might reasonably report that the mean was 9.47 (did I do that right?)</p>
<p>I never thought of this in the context of GPA’s though. My kids’ H.S. gives grades of A=4, B=3, C=2, no + or -, but the GPA’s are always reported to two significant digits: 3.92</p>
<p>(The H.S. does not rank. I think that this “carrying it out to the ten thousandth place” is a characteristic of schools that rank.)</p>