This is extremely similar to Miguel de Carvalho’s “Mean, what do you mean?” published four years earlier: https://www.maths.ed.ac.uk/~mdecarv/papers/decarvalho2

This is extremely similar to Miguel de Carvalho’s “Mean, what do you mean?” published four years earlier: https://www.maths.ed.ac.uk/~mdecarv/papers/decarvalho2016.pdf https://www.maths.ed.ac.uk/~mdecarv/papers/decarvalho2016.pd... In addition to discussing Kolmogorov’s construction of the mean (first moment), he extends it to higher moments (e.g. variance), and provides some nice examples. Pity the authors didn’t cite the aforementioned paper. Note that I’m not implying any plagiarism happened; the subject is elementary enough that different people could easily arrive at similar manuscripts independently.