Graphs are usually used to locate data or numbers easily because they are arranged in some specific order. In RD Sharma Solutions for Class 7 Maths Chapter 24 data handling 3, two main things are covered. The first one is, understanding the definition and meaning of bar graphs.
A bar graph can easily be described as a chart or a graphical representation of qualities, numbers, or data using bars and strips. They are used to compare and contrast numbers, frequencies, or any other measures of distinct categories of data. Secondly, the construction of bar graphs is taught to the students. The below mentioned are the steps involved while constructing a bar graph;
1. On a graph, draw two perpendicular lines intersecting at 0.
2. Consider the horizontal line as the X-axis and the vertical line as the Y-axis.
3. Along the horizontal axis, try choosing the uniform width of bars and the uniform gap between those bars and write the names of the data items whose values are to be marked.
4. Now, along the vertical axis, try choosing a suitable scale to determine the heights of the bars for the given set of values. Usually, frequency is taken along the Y-axis.
5. Calculate the heights of the bars according to the chosen scale, then draw the bars.
So, this is the general procedure in creating any bar graph. Using this, the students can understand bar graphs and have a clear idea of making a bar graph independently. The chapter also makes the student aware of drawing bar graphs with some given prior data. Finally, the chapter includes questions that are common and helps increase a student's knowledge of statistics.