Understanding Graphs: Bar Graphs, Histograms, and Pie Charts

These flashcards cover the essential terms and definitions related to graphing data, including bar graphs, histograms, and their key statistical concepts.

Bar Graph

A graphical representation of data where the length of bars represents the value of the variable, with spaces between each bar.

Histogram

A graphical representation similar to a bar graph but without spaces between the bars, used for numerical data.

Relative Frequency

The ratio of the frequency of a specific event to the total number of events, often represented as a percentage.

Class Width

The range of values that fall into a single bar in a histogram, defined by a lower class limit and upper class limit.

Mean (Average)

The sum of all data values divided by the number of values, representing the central value of a dataset.

Median

The middle value in an ordered dataset, which may require averaging two middle values if there is an even number of data points.

Mode

The value that appears most frequently in a dataset; there can be no mode, one mode, or multiple modes.

Symmetric Data Distribution

A distribution where the mean, median, and mode all fall at or near the same central point.

Skewed Left

A distribution that has a long tail on the left side, where the mean is less than the median.

Skewed Right

A distribution that has a long tail on the right side, where the mean is greater than the median.

Pie Chart (Circle Graph)

A circular graph that is divided into slices to illustrate numerical proportions; each slice represents a category's part of the total.

Summation Symbol (Σ)

A symbol used to indicate the sum of a set of values.

Sample Mean (x̄)

The mean calculated from a sample, denoted by x with a bar over it.

Population Mean (μ)

The mean calculated from an entire population, denoted by the Greek letter mu.

Lower Class Limit

The smallest value within a class interval in a frequency distribution.

Upper Class Limit

The largest value within a class interval in a frequency distribution.

Axes

The two lines (horizontal and vertical) that form the framework of a graph; the horizontal axis is commonly used for categories or ranges.