Important Formulas: Data Handling | Mathematics (Maths) Class 8 PDF Download

Term

1. Data

• A systematic record of facts or different values of a quantity is called data.
• Data mostly available to us in an unorganized form is called raw data.

2. Features of data

• Arranging data in an order to study their salient features is called presentation of data.
• Frequency gives the number of times that a particular entry occurs
• Table that shows the frequency of different values in the given data is called a frequency distribution table
• A table that shows the frequency of groups of values in the given data is called a grouped frequency distribution table
• The groupings used to group the values in given data are called classes or classintervals. The number of values that each class contains is called the class size or class width. The lower value in a class is called the lower class limit. The higher value in a class is called the upper class limit.
• The common observation will belong to the higher class.

3. Bar graph: A bar graph is a pictorial representation of data in which rectangular bars of uniform width are drawn with equal spacing between them on one axis, usually the x axis. The value of the variable is shown on the other axis that is the y axis.

4. Histogram: Grouped data can be presented using histogram. Histogram is a type of bar diagram, where the class intervals are shown on the horizontal axis and the heights of the bars show the frequency of the class interval. Also, there is no gap between the bars as there is no gap between the class intervals.

5. Circle Graph or Pie-chart: A circle graph shows the relationship between a whole and its part.