# Probability and Statistics

# Probability and Statistics Terms

## Get down with the lingo

### Probability

Likelihood or chance of the occurrence of an event.### Qualitative Data

Data that can be represented with qualitative features.### Quantitative Data

Data that can be represented with numbers.### Categorical Data

Data that can be organized into mutually exclusive groups or categories.### Graph

A diagram representing data or relationship(s) between variables.### Discrete Data

A type of data for which there is only a finite number of possible values.### Continuous Data

A type of data for which there is no possible separation between the possible values.### Univariate Data

Data with only one variable. Not to be confused with data on a unicycle.### Bivariate Data

Data that deals with relationships between two variables.### Mean (Average)

The sum of all the data points divided by the number of data points.### Median

The middle value of a list of data points.### Mode

The data point with highest frequency.### Quartiles

A set of points that divide the data set into three equal parts.### Stem And Leaf Plot

A representation of data where each data point is split into a leaf and a stem. The leaf is usually the last digit, and the stem consists of the other digits.### Bar Graph

A representation of data that uses rectangular bars to show the magnitude of categorical variables. Useful in all sorts of real-life situations.### Histogram

A representation of data that uses rectangular bars to show the magnitude of quantitative variables.### Pie Chart

A circular graph divided into sectors, where the area of each sector is proportional to the relative size of the quantities represented. Also incredibly useful in real life.### Box And Whisker Plot

A representation of data that displays the range and quartiles of the data set. Looks like a kitty cat when you squint and tilt your head to the left.### Interquartile Range

The difference between the third and the first quartile.### Outliers

Data points that are numerically far away from the rest of the data set. The loners of the group, if you will.### Scatter Plot

A graph of points showing the relationship between two variables.### Linear Regression

Fitting a straight line to a set of data points to find the linear relationship between the dependent and independent variables.### Correlation

The measure of the linear relationship between two variables. Is not causation.### Odds

The ratio of the probability that an event will happen to the probability that it will*not*happen.

### Event

A set of outcomes of an experiment.### Mutually Exclusive Event

Events A and B are mutually exclusive if the occurrence of event A implies event B cannot occur.### Independent Event

Events A and B are independent if the outcome of event A has no effect on the outcome of event B. It's grown up! It can do what it wants!### Factorial

*n*! =

*n*× (

*n*– 1) × (

*n*– 2) . . . × 2 × 1. The most excited of all key terms.