After completion of this chapter, students will be able to:

- Construct Cumulative Frequency Table.
- find the mean, median and quartile of grouped data.
- find the mean, median and quartile of non- grouped data.
- find the mean, median and quartile of grouped data.

When the frequency of each class is added in succession, the total frequency is called cumulative frequency and is denoted by c.f. The average value of data is called mean. data is grouped in individual, discrete and continuous series. When a given distribution arranged either ascending or in descending order then the value that lies in the middle of the distribution is called median.In the given data the most repeated value or data is called mode.