Apoor girl out with geometry lol the directions are: find the missing side. round to the nearest tenth. i know it has to do with tangents, cosine, and sine and stuff. the answer is below the problem (is shown) i just need the work! < 3

Ameteorologist is studying the monthly rainfall in a section of the brazilian rainforest. she recorded the monthly rainfall, in inches, for last year. they were: 10.4, 10.3, 11.7, 11.1, 8.0, 4.4, 2.6, 1.8, 2.5, 4.4, 7.3, 9.5 fill in the missing values in the formula. what is the variance?