user51547

Your concern about being able to make the same argument for any fixed difference is a valid one. The problem with these types of arguments is that you're coming up with a test post hoc/after seeing the data. One way you could get around this issue is to first to decide on a test, ask your friend to sample more points, and test on that new sample (but maybe that is against the spirit of your question).

You could frame this as a hypothesis test (essentially all the commonly used tests e.g. Kolmogorov-Smirnov would reject that this sample came from a standard normal distribution en.wikipedia.org/wiki/Normality_test), but it's worth noting there's a post hoc testing issue here.

anyone here?