Short answers, pulled from the story.
Gottfried Achenwall coined the German word statistik in 1749 as a summary of how things stand. The term evolved from the Latin status meaning situation or condition in society to mean state in late Latin.
The Hawthorne effect describes outcomes changing due to observation itself rather than the manipulated variable. This phenomenon emerged during the Hawthorne study which examined worker productivity at the Western Electric Company plant by modifying illumination levels.
Francis Galton introduced standard deviation, correlation, regression analysis, and applied these methods to human characteristics like height and weight. Karl Pearson developed the product-moment correlation coefficient and founded Biometrika as the first journal of mathematical statistics.
Ronald Fisher coined the term null hypothesis during his Lady tasting tea experiment in 1935. He stated this hypothesis is never proved or established but possibly disproved through experimentation.
Adrien-Marie Legendre described the method of least squares in 1805 though Carl Friedrich Gauss used it earlier in 1795. Formal discussions on inference date back to mathematicians and cryptographers of the Islamic Golden Age between the 8th and 13th centuries.