Concise Selina Solutions for Class 9 maths Chapter 29 Graphical Representation (Histograms and Ogives)

A statistical data can be expressed by the diagram, chart, etc., to make the data grasped immediately. In this chapter, students will be studying only about histograms, frequency polygon and Ogive (cumulative frequency curve). Graphical representation refers to the use of charts and graphs to visually display, analyse, clarify, and interpret numerical data, functions, and other qualitative structures.

Thus, a histogram is a graphical representation of a frequency distribution with class intervals or attributes as the base and frequency as the height. The key difference is that histograms have bars without any spaces between them and the rectangles need not be of equal width.

Cumulative histograms, also known as ogives, are graphs that can be used to determine how many data values lie above or below a particular value in a data set. An ogive (oh-jive), sometimes called a cumulative frequency polygon, is a type of frequency polygon that shows cumulative frequencies. In other words, the cumulative percents are added on the graph from left to right. An ogive graph plots cumulative frequency on the y-axis and class boundaries along the x-axis Ogives are graphs that are used to estimate how many numbers lie below or above a particular variable or value in data. The most commonly used graphs of the frequency distribution are histogram, frequency polygon, frequency curve, Ogives (cumulative frequency curves).