(

probability theory:)

Probability speak for a

measurable function on a

probability space (i.e. a

measure space of total measure

1).

Random variables are the formalisation of the concept of the result of an experiment. You have a system with a random element (your probability space); you perform a measurement. The result is a deterministic function of the state of your system, but your system itself is random. So the result is a random variable.

- The number of heads in a sequence of 163 coin tosses.
- The average value of the results from rolling 17 dice (you'd
*expect* this to be roughly 3.5, but since you're dividing by an odd number you'll never get this number!).