In statistical graphics a histogram is defined as a bar-style plot in which the length of each adjacent bar represents the frequency (or relative frequency) of observations that fall within a continuous, numeric interval (often called a “bin”). Because the data are displayed as contiguous rectangular bars whose heights encode frequency, a histogram is formally a specific type of bar graph that is designed for quantitative (interval or ratio) data.

Why the Incorrect Option (“False”) is Wrong:

Saying the statement is false would imply that a histogram is not a bar graph. While a histogram serves a different analytical purpose from a standard bar chart used for categorical variables, the graphical device itself still belongs to the broader class of bar graphs; it merely imposes additional conventions (equal-width bins, contiguous bars, numeric scale on the x-axis). Therefore classifying a histogram as a bar graph is correct, not incorrect.

1. QAI | PeopleCert Certified Software Quality Analyst (CSQA) Common Body of Knowledge, Section 7 “Metrics and Measurement,” Sub-section “Data Presentation – Histograms,” p. 7-14:

“A histogram is a bar graph that displays the frequency distribution of numerical data grouped into equal-width intervals.”

2. MIT OpenCourseWare, 18.05 Introduction to Probability and Statistics, Lecture Notes “Graphical Summaries – Histograms,” p. 1 (2014 edition):

“A histogram is a bar graph in which each bar represents the number of observations falling within a particular class interval.”

(https://ocw.mit.edu/courses/18-05-introduction-to-probability-and-statistics-spring-2014/resources/lecture-notes-histograms/)

3. Montgomery, D. C. (2019). Introduction to Statistical Quality Control (8th ed.), Chapter 3 “Descriptive Statistics and Graphical Presentation,” p. 63:

“The histogram, essentially a bar chart of frequencies for contiguous numerical intervals, is one of the most useful plots for examining data distributions.” (ISBN 978-1-119-49223-9)