Probability, density, function, PDF

https://en.wikipedia.org/wiki/Probability_density_function

https://en.wikipedia.org/wiki/Fair_coin

https://online.stat.psu.edu/stat414/lesson/14/14.1

https://ru.wikipedia.org/wiki/%D0%9F%D0%BB%D0%BE%D1%82%D0%BD%D0%BE%D1%81%D1%82%D1%8C_%D0%B2%D0%B5%D1%80%D0%BE%D1%8F%D1%82%D0%BD%D0%BE%D1%81%D1%82%D0%B8

http://statistica.ru/glossary/general/plotnost-raspredeleniya-veroyatnostey/

http://mathprofi.ru/nepreryvnaya_sluchaynaya_velichina.html

https://mipt.ru/education/chair/mathematics/study/methods/%D0%A1%D0%92%D0%B8%D0%A0_%D0%A1%D0%B0%D0%BC%D0%B0%D1%80%D0%BE%D0%B2%D0%B0(2).pdf

https://mgsu.ru/universityabout/Struktura/Kafedri/Prikladnoy_matem/teaching-materials/lectures-teachers/kagan/13-01-Kagan-2.pdf

https://math.semestr.ru/math/expectation-continuous.php

https://yukhym.com/ru/sluchajnye-velichiny/plotnost-raspredeleniya-veroyatnostej.html

https://congyuzhou.medium.com/%D0%BF%D0%BB%D0%BE%D1%82%D0%BD%D0%BE%D1%81%D1%82%D1%8C-%D1%80%D0%B0%D1%81%D0%BF%D1%80%D0%B5%D0%B4%D0%B5%D0%BB%D0%B5%D0%BD%D0%B8%D1%8F-%D0%B2%D0%B5%D1%80%D0%BE%D1%8F%D1%82%D0%BD%D0%BE%D1%81%D1%82%D0%B5%D0%B9-31d19a680f16