Probability

variable

A characteristic that changes or varies over time and/or for different individuals or objects under consideration

Sample

A representative part of a population

Z-score

The relative standing of a measurement in a data set.

Mean

the ‘average’. Dividing all data values by the number of them.

Median

The ‘mid-point’ of data.

Range

Largest-smallest

Experiment

The process by which an observation(or measurement) is obtained.

Mutually exclusive

If when one event occurs, the other cannot and vice versa

Union (A U B)

the event that either A or B both occur

Intersection (A ∩ B)

the event that both A or B can occur

Conditional probability

The probability of event A, given that event B has occured.

Theoritical probability

Using existing knowledge to determine the probability of an event occuring

Experimental probability

Run an experiment to estimate the actual probability

Sample space

A list of possible outcomes in an experiment

Relative frequency

Probability calculated based on experimental/real data.

Independent event

When the probability of one occurring does not affect the probability of the other occurring

(eg: Tossing a coin and rolling a die)

When two events, A and B, are independent:

P(A and B) = P(A) x P(B)

Absolute risk

Probability for a particular group

Favourable outcome

What we want to happen(the outcome we would like to have/investigating)

Total number of outcomes

Describes the absolute maximum number of favourable outcomes we could have.

Usually the size of the population we are measurign from.

population

The set from which a sample of data is selected

Outcome

all of the possible results

coins landing on heads, tails