M2A Review on Probability

Probability

means possibility. It is a branch of mathematics that deals with the occurrence of a random event. The value is expressed from zero to 1.

Experiment

- process where specific results are obtained

Outcome

single result of a probability experiment

Sample Space

- set of all possible outcomes for a probability experiment Rolling a pair of dice has a sample space of 36 outcomes [(1,1). (1,2), (1,3), (1,4) ...etc. or just simply 6 x 6)

Event

- set of outcomes of a probability experiment; a subset of the sample space

Simple event

- one outcome (rolling 4 in one die)

Compound event

- two or more outcomes (rolling an even number on a die then getting a head in a toin coss)

Classical Probability

Each outcome in a sample space is equally likely to occur.

Empirical Probability

Each outcome in a sample space is NOT equally likely to occur.

Subjective Probability

An educated guess or estimate.

Four key rules in Probability

• The probability of an event is always between 0 and 1. No negative probabilities or greater than 1.

• The sum of all outcomes in a sample space is always equal to 1.

• If it is impossible for an event to occur, the probability of that event is O.

• If the event is certain to occur. the probability is 1.

Permutation

• is an arrangement of objects where order matters.

• Ex. Arranging books on a shelf, Assigning positions, Creating passwords, Ranking contestants, Seating people in specific seats

Combination

• is a selection of objects where order does not matter.

• Ex. Selecting committee members, Choosing team members, Selecting representatives, Choosing lottery numbers, Selecting products for a basket