Apower plant measures its emissions by putting a sensor 1 mile upwind (in the opposite direction of the wind) of the plants smokestack. will the reading this sensor provides be a random sample of the plants emissions?

The reading that the sensor will provide will be random samples of the different plant emissions. This is because 1 mile is quite a long distance already, if samples are to be tested that far, it is not guaranteed that the samples are really what they are to be.

It's like discovering the answer to a puzzle. the purpose in solving an equation is to find the value or values of the variable that makes it a true statement. any value of the variable that makes the equation true is called a solution to the equation.