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.

In order to draw meaningful inferences from any data, we need to organise the data systematically.

Frequency gives the number of times that a particular entry occurs.

Raw data can be ‘grouped’ and presented systematically through ‘grouped frequency distribution’.

Statistics: The science which deals with the collection, presentation, analysis and interpretation of numerical data.

Observation: Each entry (number) in raw data.

Range: The difference between the lowest and the highest observation in a given data.

Array: Arranging raw data in ascending or descending order of magnitude. Data can also presented using circle graph or pie chart. A circle graph shows the relationship between a whole and its part.

There are certain experiments whose outcomes have an equal chance of occurring. A random experiment is one whose outcome cannot be predicted exactly in advance. Outcomes of an experiment are equally likely if each has the same chance of occurring.

Frequency: The number of times a particular observation occurs in the given data.

Class Interval: A group in which the raw data is condensed.

(i) Continuous: The upper limit of a class interval coincides with the lower limit of the next class.