For data to be useful, it is very important to collect complete, accurate & relevant data.
After collection of data, it is necessary to represent data in a precise manner so that it is easily understood. Representation of data in a visual manner is known as its Graphical Presentation or simply, Graphs. Data can also be presented in the form of a table; however a graphical form is easier to understand. Consider the family of Mr. Khanna. They are very fond of eating ice-creams. Some like butterscotch, some like vanilla flavor, some like strawberry and the rest of them likes chocolate. Some demand cones & some of them demand cups. A child of VIII class decides to construct the graphs according to their amount of icecreams consumed. There are 7 ways of representing the data.
• The numerical information is called data.
• Data can be arranged and presented by grouped frequency distribution.
• Frequency is the number of times a particular entry occurs.
• Histogram is a special type of bar graph in which the class intervals are shown on the horizontal axis and heights of the bars correspond to the frequency of the class.
• In a histogram there is no gap between bars.
• A circle graph or a pie chart shows the relation ship between a whole and its parts.
• Outcomes of an event or experiment are equally likely if each has the same of occuring.
• Probability of an event
• Probability of an event can have a value from 0 to 1.
• Probability of an impossible even is 0.