Question

Distinguish between:

1) Bar diagram and pie - diagram

2) Histogram and Bar diagram

3) Frequency polygon and frequency curve.

Answer 1

1.

Basis of Difference	Bar Diagram	Pie Diagram
Meaning	It is a graphical representation of data using bars of different heights.	It is a graphical representation of data in the form of circles or pie charts.
Method of presentation	Data is presented in terms of percentages or actual variables.	Data is presented in terms of degrees (as components out of 360 degrees).
Significance of the area depicted by the diagram	The width of the rectangle in a bar (area under each vertical bar) diagram is of no significance.	The area of the segment in a pie graph is of great significance.

2.

Basis of Difference	Histogram	Bar Diagram
Meaning	It is a form of representing data through vertical bars whose areas are proportional to the given frequencies.	It is a graphical representation of data using bars of different heights.
Kind of data for which useful	It can only be drawn for continuous data.	It can be drawn for both discrete and random data.
Significance of the width of bars	Width of the rectangles represents class width and is equally important as the height of the bar.	Width of the rectangle in a bar graph is of no significance.

3. A frequency polygon is a closed figure that is formed by joining the top midpoints of all the rectangles of histograms using a straight line.On the other hand, frequency curve is a curve that is obtained by joining the top midpoints of all rectangles of a histogram using a free hand. The only difference between a frequency curve and a frequency polygon is that while, frequency polygon is drawn by joining the points by a straight line, frequency curve is drawn by a smooth hand.