I'm attempting to compute statistical significance for two data sets. I have the mean and the number of data points, but I don't think I can compute std deviation, because I don't have the individual data points.
Under previous teacher, 1,072 tests given with average score of 27.7 correct.
New teacher, 179 tests given with average score of 28.6.
Seems self-evident to me that combination of small uptick and tiny sample size means that conclusion "new teacher responsible for improvement" is untenable, but I'd like to be able to say that the improvement is not statistically significant.
All help appreciated.