The answer is 0.36. I don't think u need to explain why, right ;)
1.)100+80+7+0.5+0.04 or you could do it like 2.)1x100+8x10+7x1+5x0.1+4x0.01
Using it's concept, it is found that the variance of the data-set is of 1.15.
The mean of a data-set is the <u>sum of all observations divided by the number of observations,</u> hence:

The variance is the <u>sum of the differences square between each value and the mean, divided by the number of values</u>. Hence:
![V(X) = \frac{1}{10}[(9 - 7.15)^2 + (7 - 7.15)^2 + (6.5 - 7.15)^2 + (7.5 - 7.15)^2 + (7 - 7.15)^2 + (8 - 7.15)^2 + (5 - 7.15)^2 + (6 - 7.15)^2 + (7.5 - 7.15)^2 + (8 - 7.15)^2] = 1.15](https://tex.z-dn.net/?f=V%28X%29%20%3D%20%5Cfrac%7B1%7D%7B10%7D%5B%289%20-%207.15%29%5E2%20%2B%20%287%20-%207.15%29%5E2%20%2B%20%286.5%20-%207.15%29%5E2%20%2B%20%287.5%20-%207.15%29%5E2%20%2B%20%287%20-%207.15%29%5E2%20%2B%20%288%20-%207.15%29%5E2%20%2B%20%285%20-%207.15%29%5E2%20%2B%20%286%20-%207.15%29%5E2%20%2B%20%287.5%20-%207.15%29%5E2%20%2B%20%288%20-%207.15%29%5E2%5D%20%3D%201.15)
A similar problem is given at brainly.com/question/1527299