In our daily life we come across numerical data in advertisements, newspapers and at other places. These data may relate to the cost of living, cricket average, profits of a company and so forth.

For example, if we look into a newspaper, we may find a weather report giving pertinent data about the maximum and minimum temperatures and rainfall of various important cities of a country.

We can show these data with the help of graphs because numerical figures are more convenient and easy to understand, leaving a pleasing effect on observer's mind. We can easily analyze the given data with the help of graphs. Data recorded in experiments or surveys is displayed by a statistical graph.

## Types of Statistical Graphs

Given below are the most common graphs used in statistics.

Bar graph:  A bar graph is a pictorial representation of statistical data in which the independent variable attains only the discrete value. The dependent variable can either be discrete or continuous and is used to represent bars of different heights. It may be horizontal or vertical.

Bar graphs are probably the most popular and most widely used graph types. Bar graphs gives a graphical representation of data in different categories or groups.
The greater the length or height of a bar, greater will be their value.Fruit:     Apple     Orange     Banana     Kiwifruit    Blueberry   Grapes
People:      35         30            10            25           40            5

From the above graph we see that Blueberry is most popular and grapes are least popular.

Dot plot: This is the oldest way to show any data in graph. In this method we use dots(filled circles) for each value in the given sequence on the two rectangular axis.

If any value comes more than once, we can place one dot over another dot to represent the repetition of the value in the given data. This method is used when the number of values is relatively small.

Histogram: This is a type of bar graph which is used to represent continuous data. Histograms gives visual information of the given continuous numerical data that lie within a class or a range of values. In histogram, we can use rectangles to represent the numerical data.
The widths of these rectangles, indicates class intervals and the corresponding frequencies are proportional to the areas of these rectangles.

Pie chart: Pie chart is a special chart which uses "pie slices" to show relative sizes of data. It is a circular chart in which we divide the circle into sectors.They are used to compare different parts in the given data. Given below is the Product Y which is used to represent the percentages present in a given quantity.

Stem-and-leaf plot: A stem-leaf-plot is a method which is used to represent statistical data. in this method we can split each data value into a stem and a leaf. In the graph stem values are placed in column and leaf values are placed at the left side of the stem values.

Pictograph: Pictograph is used to represent statistical data using appropriate images to match the frequencies of different kinds of data .Each image will consist of different things in it.

It is always interesting to represent data through a pictograph but the drawback is it will not be accurate. From the below graph we see that thursday has 100 smileys which is the highest and wednesday contains 40 smileys which is the least.

Scatter Plot: If two factors are related then to show the relationship between these two we can use scatter-plot. With the help of this graph we can determine negative correlation, positive correlation or no correlation. Here we see that for the given data the points are positively skewed.

Box and Whisker Plot: This is the only graph in which we can show the five point summary.
For comparing two or more than two data, we draw multiple boxes side by side and compare the data.