Question

choose the most apt description of expected value.
the median of a random variable.
the long - term average outcome of an experiment.
what you should expect to happen in an experiment every time.
the best result you can hope for in an experiment.
the standard deviation of a random variable.

Explanation:

The expected value of a random variable represents the long - term average outcome of an experiment. The median is the middle value when data is ordered. The standard deviation measures spread. Saying "the best result you can hope for" is not a formal statistical description. And "what you should expect to happen every time" is incorrect as random variables have variability.

Answer:

The long - term average outcome of an experiment.