Experiment

Repeated a fixed number of times and each repetition is known as a trial.

Outcome

Possible result of an probability experiment.

Sample Space

The set of all possible outcomes.

Probability

The ratio of a number of ways a certain event can occur to the number of possible outcomes.

Complement of an Event

The subset of outcomes in the sample space that are not in the event.

Theoretical Probability

The ratio of the number of favorable outcomes to the number of possible outcomes.

Experimental Probability

Probability based on actual experiments and adequate recordings of the happening of events.

Fundamental Counting Principle

If event **M** can occur in **m** ways and
is followed by event **N** that can occur in
**n** ways, then the event **M** followed by
event** N** can occur in **m * n** ways.

Compound Events

Two or more simple events.

Independent Events

Two or more events in which the outcome of one even does not influence the outcome of the other event(s).

Dependent Events

Two or more events in which the outcome of one event does affect the outcome of the other event(s).

Population

A discrete group of people, animals or things that can be identified by at least one common characteristic for the purposes of data collection and analysis.

Sample

A subgroup or subset of a population used to represent the whole population.

Unbiased Sample

A random sample that is representative of a larger sample.

Biased Sample

A random sample that is not representative of a larger sample.

Mean

The sum of data divided by the numb of items in the data set.

Median

The middle number in a set of data when the data are arranged in numerical order.

Mode

The number or numbers that occur(s) most often in a set of data.

Measures of Central Tendency

For a list of numerical data, numbers that can represent the whole set of data.

Range

A measure of variation that is the difference between the least and greatest values in a set of data.

Outlier

Data that are more than 1/5 times the interquartile range beyond the quartiles.

Mean Absolute Deviation

The average of the absolute values of differences between the mean and each value in a data set.

Box & Whisker Plot

A diagram that divides a set of data into four parts using the median and quartiles.

Lower Extreme

The smallest or least number out of a data set, usually farther away from interquartile range than other data in set.

Upper Extreme

The largest or biggest number out of a data set, usually farther away from interquartile range.

Lower Quartile

The median of the lower half of a set of data.

Upper Quartile

The median of the upper half of a set of data.

Interquartile Range

The range of the middle half of a set of data The difference between the upper quartile and lower quartile.

Scatter Plots

The relationship between a set of data with two variables, graphed as ordered pairs on a coordinate plane.

Line of Fit

On a scatter plot, a line drawn that is very close to most of the data points.

Two Way Table

A way to display frequencies or relative frequencies for two categorical variables.

Relative Frequency

The ratio of the actual number of favorable events to the total possible number of events.

Measures of Variation

Used to describe the distribution of statistical data.