12. Statistics
- 1. NUMBER SYSTEMS
- 2. A POLYNOMIALS
- 3. COORDINATE GEOMETRY
- 4. LINEAR EQUATIONS IN TWO VARIABLES
- 5. INTRODUCTION TO EUCLID'S GEOMETRY
- 6. LINES AND ANGLES
- 7. TRIANGLES
- 8. QUADRILATERALS
- 9. CIRCLES
- 10. HERON'S FORMULA
- 11. SURFACE AREAS AND VOLUMES
- 12. STATISTICS
- 13. APPENDIX 1: PROOFS IN MATHEMATICS
- 14. APPENDIX 2: INTRODUCTION TO MATHEMATICAL MODELLING
Introduction - Learning Objectives
12.1 Graphical Representation of Data
Bar Graphs
A bar graph is a pictorial representation of data in which bars of uniform width are drawn with equal spacing between them, depicting the variable on one axis and its values on the other axis.
Histograms
A histogram is similar to a bar graph but is used for continuous class intervals. The widths of the bars represent the class intervals, and their heights are proportional to the frequencies.
Frequency Polygons
A frequency polygon is another way to visualize quantitative data. It is formed by joining the midpoints of the upper sides of adjacent rectangles in a histogram.
Example 1:
Represent the number of students born in different months using a bar graph.
Exercise 12.1
- Draw a bar graph to represent the number of girls per thousand boys in different sections of Indian society.
- Draw a histogram showing the frequency distribution of the length of leaves in a plant.
- Compare the performance of students in two sections using frequency polygons.