[bransonf]

That professor was wrong or your understanding is.

There are plenty of statistically viable ways to determine differences between groups. Even a simple T-test is usually sufficient.

The difference of means does not have to be more than the range in either group. Standard deviation is what’s important here. You use a test statistic to determine the relative value of the real mean within a confidence interval. It’s whether these intervals overlap that you can determine a significant difference between groups.

[travisoneill1]

I know that the professor was wrong. That was the point of the comment. That a professor in a so called science class could get the math so comically wrong.