Statistics

Statistics

Statistics is the science of making effective use of numerical relating to groups of individuals or experiments.
Statistics is an attractive way of putting numbers across,statistics is about collection of information and its presentation and about drawing inferences from these. We come across facts and figures in the newspapers, Television and the radio. The numerical figures are called "the data".

Here are few terms that are most commonly linked to statistics:

A list of some important terms as follows: (i) ungrouped data (ii) tabulation of data (iii) range (iv) frequency (v) frequency distribution (vi) tally (vii) inclusive type of grouped frequency distribution (viii) exclusive type of grouped frequency distribution (ix) lower limit and actual lower limit (x) upper limit and actual upper limit (xi) class size or class width (xii) class mark or class mid-interval (xiii) Variables (xiv) Continuous Variables (xv) Discrete Variables.

Probability involves a lot of graphical representation of data.Figures are the most commonly used modes of graphical representation.The different types of graphs that we are going to study are 1. Bar graphs 2. Pie charts 3. Frequency polygon 4. Histogram.

Bar Graph

This is the simplest type of graphical presentation of data. The following types of bar graphs are possible: (a) Simple bar graph (b) Double bar graph (c) Divided bar graph.

Pie Graph or Pie Chart

Sometimes a circle is used to represent a given data. The various parts of it are proportionally represented by sectors of the circle. Then the graph is called a Pie Graph or Pie Chart.

Frequency Polygon

In a frequency distribution, the mid-value of each class is obtained. Then on the graph paper, the frequency is plotted against the corresponding mid-value. These points are joined by straight lines. These straight lines may be extended in both directions to meet the X - axis to form a polygon.

Histogram

A two dimensional frequency density diagram is called a histogram. A histogram is a diagram which represents the class interval and frequency in the form of a rectangle.
What do we mean by a Graphical representation of Data???

Graphs and diagram leave a lasting impression on the mind and make intelligible and easily understandable the salient features of the data. Forecasting also becomes easier with the help of graph. Thus it is of interest to study the graphical representation of data.