Frequency curve

1. FREQUENCY CURVE
1. Frequency curve is a graph of frequency distribution where the line is smooth.
2. It is just like a frequency polygon. In the polygon is line is straight, but in the curve the
line is smooth.
3. It is an area diagram.
4. It is the graphical representation of frequency distribution.
5. The X-axis is marked with class intervals.
6. The Y – axis is marked with frequencies.
7. A histogram is drawn. The midpoints of the top of the rectangles are joined by a smooth
line.
8. The beginning and end of the curve should touch the x – axis at the mid points of first
and last class interval.
9. The area of the curve is equal to that of a histogram.
10. The frequency curve is divided into 3 types based on the shape of the curve. They are
1. Normal distribution curve
2. Positively skewed distribution curve
3. Negatively skewed distribution curve.
11. The normal distribution curve is symmetrical and has an inverted bell shape.
12. The positively skewed distribution curve is asymmetrical. The low values of the
variables have the highest frequencies.
13. The negatively skewed distribution curve is also asymmetrical. High values of the
variables have the highest frequencies.
Uses of frequency Curve:
1. It gives a clear picture of the entire data.
2. It is easily memorized.
3. It facilitates comparison of two or more frequency distributions on the same graph.
4. It gives an idea of the pattern of distribution of variables in the population.