Qm 214 4.5 & 4.2

0!=

1

The conditional probability of A given B is calculated by dividing the probability of intersection of A and B by the probability of

B

Factorial formula-

The number of ways to assign every member of a group of size n to n slots

Permutation formula-

The number of ways to choose x objects from a total of n objects, where the order in which the x objects is listed does matter

Combination formula-

The number of ways to choose x objects from a total of n objects, where the order in which the x objects is listed does not matte

Conditional probability-

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

Unconditional probability-

The probability of an event without any restriction.

Complement rule-

The probability of the complement of an event is P(Ac) = 1 - P(A).

Multiplication rule-

The probability that A and B both occur is P(A ∩ B) = P(A|B)P(B).

Addition rule-

The probability that A or B occurs, or that at least one of these events occurs, is P(A ∪ B) = P(A) + P(B) − P(A ∩ B).

Which of the following is an example of a conditional probability?

The probability that Lisa purchases groceries, given that Neil has already purchased groceries.

For any given event, the probability of that event and the probability of the

complement of the event must sum to one.

Using the multiplication rule, the probability that event A and event B both occur is computed by multiplying the conditional probability of event Agiven event B by the probability of...

event B

n! denotes a

factorial

It is common to refer to P(A ∩ B) as the

joint probability of events A and B.

THE FACTORIAL FORMULA-

n! = n x (n - 1) x (n - 2) x ... x 2 x 1

THE PERMUTATION FORMULA-

nPx = n!/(n-x)!

The addition rule is used to calculate...

the union of two events.

To calculate the probability of the union of two mutually exclusive events A and B,

we add the probability of A to the probability of B.

For mutually exclusive events A and B, the joint probability is

zero