# chp.7 randomness and probability

## 33 terms

### random phenomena

we can't predict the individual outcomes, but we can hope to understand characteristics of their long run behavior

each attempt

outcome

event

sample space

frequency

does not

### ______ stated that if the events are independent, then as the number of trials increases, the long-run relative frequency of an event gets closer and closer to its probability.

law of large numbers (LLN)

repetitions

### why does the law of average not exist?

things balance out in the long run bc the unbalances events get outnumber by the large total number of outcomes, not by a string of opposite outcomes

### theoretical probability can be computed by:

# of outcomes in "A" / total # of outcomes

can not

always

### the probability of the set of all possible outcomes must be equal to what number?

one; P(S)=1 S represents the set of all possible outcomes and is called the sample space

### the complement rule says that the probability of an event occurring is 1 - the probability that it does or does not occur

does not occur; P(A)= 1-P(A^c) A^c=complement

### for two independent events, A and B, how do you find the probability that both A and B occur

multiply them together P(A and B)= P(A) x P(B)

### if two events have no outcomes in common, they are

disjoint aka mutually exclusive

### the addition rule allows us to add the probability of ______ events to get the probability that either event occurs

disjoint P(A or B) = P(A) + P(B)

### the general addition rule calculates the probability of ______ of the two events occurs

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

margins

two

### probability that takes into account a given condition is called

conditional probability

can not

true

one

disjoint

independent

### probability is based on __________

long run relative frequencies

long run

averages

conditional

0 and 1

1