Probability Flashcards
What is the formula for probability?
probability = (number of successful outcomes) / number of total outcomes
If you were conducting an experiment where you roll a dice and hope for an even number, what is the trial?
The rolling of the dice.
If you were conducting an experiment where you roll a dice and hope for an even number, what is the event?
Rolling an even number.
If you were conducting an experiment where you roll a dice and hope for an even number, what are the outcomes?
Any possible results; 1, 2, 3, 4, 5, 6.
When are a set of events exhaustive?
If the events cover all the possible outcomes.
When are two events mutually exclusive?
If there is no overlap between them.
If two events are mutually exclusive:
P(A or B) = P(A) + P(B).
P(A ∪ B) = P(A) + P(B).
What does ∪ mean?
It is the union symbol and means ‘or’.
When are two events not mutually exclusive?
If there is an overlap between them.
P(A or B) = P(A) + P(B) - P(A and B)
P(A ∪ B) = P(A) + P(B) - P(A ∩ B)
What does ∩ mean?
The intersection symbol and means ‘and’.
When are two events independent?
If the occurrence of one event does not affect the chances of the other one happening.
P(A and B) = P(A) x P(B)
P(A ∩ B) = P(A) x P(B)
When are two events dependent?
If the outcome or occurrence of the first affects the outcome or occurrence of the second.
P(A / B) = P(A and B) / P(B)
P(A / B) = P(A ∩ B) / P(B)
What is the formula for relative frequency?
relative frequency = number of occurrences / number of trials
What is the formula for expected frequency?
expected frequency = probability x number of trials
What is the formula for relative frequency?
relative frequency = number of occurrences / number of trials
What is the formula for expected frequency?
expected frequency = probability x number of trials
