The data which arranged properly are called arrayed data. If the data are not arranged properly then they are said raw data . Data are always can be present in a bar graph or in a line graph.: The data which is presented single or the graph which is drawn to present single type of data is called simple bar graph . In a simple bar, data are equally wide . The height of the bars represents the frequency at the data.Multiple bar graph is drawn to or more than two related components of the given data.The single number which represents the central value of a set of data is known as average .The above note give information about mean and to calculate it also .