8th Grade FAST Mathematics Pre-Algebra Practice Test

Experimental probability is the probability estimated from actual trials of an experiment. By repeating the experiment many times and recording outcomes, you use the observed frequency to estimate how likely the event is. For example, flipping a coin many times and recording how often it lands heads gives the experimental probability as the ratio of heads to total flips. As you gather more data, this observed probability tends to settle toward the true likelihood. This differs from theoretical probability, which is calculated from assumed outcomes without doing the experiment; the complement of an event is the probability that the event does not occur; and a probability distribution lists all possible outcomes of a random variable and their probabilities, not just the result of a single trial.