Let the random variable X be the outcome of rolling a 6-sided die. Assuming the die is fair, the probability is as follows: X | 1 | 2 | 3 | 4 | 5 | 6
Probability | 1/6 | 1/6 | 1/6 | 1/6 | 1/6 | 1/6

What is the variance of X?

Can someone answer it, and plot it, for 20 points and brainliest answer? p.s. they're the same ! : )

An automated water dispenser fills packets with one liter of water on average, with a standard deviation of 5 milliliter. the manual says that after a year of operation the dispenser should be tested to see if it needs recalibration. a year later a number of filled packets are set aside and measured separately. it is found that the average packet now contains about 0.995 liters. does the dispenser need calibration? explain your answer.

For which pair of functions is (gof)(a)=|a|-2?