Final answer:
The mean value of a random variable x is the expected value or average. It represents the long-term average or the value you would expect to obtain if you repeated an experiment many times.
Step-by-step explanation:
The mean value of a random variable x is also known as the expected value or the average. It represents the long-term average or the value you would expect to obtain if you repeated an experiment many times. For example, if X represents the number of heads you get when you toss three fair coins, the expected value of X would be the number of heads you would expect to get on average for each three tosses.