AP Statistics Probability Rules

Front

What is the probability of getting heads on the next flip of a fair coin after getting heads 10 times in a row?

Back

50% - Each flip of a fair coin is independent of previous flips.

Front

What is the formula to calculate the probability of either event A or event B occurring?

Back

P(A or B) = P(A) + P(B) - P(A and B)

Front

If 57% of students eat breakfast and 80% of those floss their teeth, what is the probability that a randomly chosen student eats breakfast or flosses their teeth?

Back

91% - Use the formula for the union of two events.

Front

What is conditional probability?

Back

The probability of an event occurring given that another event has already occurred.

Front

What is the formula for conditional probability?

Back

P(A|B) = P(A and B) / P(B)

Front

If 33 out of 54 females are democrats, what is the probability that a randomly selected female is a democrat?

Back

.61 - This is an example of conditional probability.

Front

What is the probability that a randomly chosen bike has a kick stand given that it has a water bottle holder?

Back

56.7% - This is calculated using conditional probability.

Front

What is the total probability of an event?

Back

The sum of the probabilities of all possible outcomes of that event.

Front

If 100 people were surveyed and 49% are democrats, how many are democrats?

Back

49 - This is calculated as 49% of 100.

Front

What does it mean if two events are independent?

Back

The occurrence of one event does not affect the probability of the other event.