sorry for the late reply... semester tests. it's mathematical science -> mathematical statistics -> statistics.
the definition of science, in particular, is: " Knowledge acquired by study; acquaintance with or mastery of any department of learning. Also pl. (a person's) various kinds of knowledge." oxford dictionary. hence, psychology is a science. economics, mathematics are sciences. statistics, philosophy, chemistry are sciences? need i continue?
you have such a narrow view in this... and random numbers/quantities/qualities, in general, stochastic variables, appear everywhere. you think people have bad marks because they want to? people want to get involved in car accidents? people want to get infected by some disease? no, it's just that they're part of a statistic.