Frequency Distributions

Frequency Distribution

A display of the values that occur in a data set and how often each value or range of values occurs.

Ordered Array

An ordered list of data from largest to smallest or vice versa.

Ungrouped Frequency Distribution

A distribution where each category represents a single value.

Grouped Frequency Distribution

A distribution where each category represents a range of values.

Frequency (f)

The numbers of data values in the frequency distributions.

Class

A category of data in a frequency distribution.

Lower Class Limit

The smallest number that can belong to a particular class.

Upper Class Limit

The largest number that can belong to a particular class.

Class Width

The difference between the lower limits or upper limits of two consecutive classes.

Class Boundary

The value that lies halfway between the upper limit of one class and the lower limit of the next class.

Class Midpoint

The value in the middle of the class, calculated as the sum of the lower limit and the upper limit divided by 2.

Relative Frequency

The fraction, or percentage, of the data set that falls into a particular class, calculated as f over n.

Cumulative Frequency

The sum of the frequencies of a given class and all previous classes.