Descriptive statistics is the branch of statistics that deals with the quantitative description of the basic features of data collection. Descriptive statistics aim is to rearrange the data in a sequence and at the end summarize the data and represent the data in the form of graphs, tables etc…for the evaluation of results. At the end descriptive statistics give a typical value that provides some estimate of the largest and smallest typical value.

## Methods

There are various methods of selecting a “typical value” from a group containing large data. These are;

- Average method (the most common method)
- Mean method (same as average method, but result varies for grouped data)
- Median method
- Mod method

Average method is the most common, because it is very simple to evaluate. For an average value, add up all the grouped data and divide it by a number that is the sum of the total number of data items in the same group.

### Example

**Statement**

You have given the weight of ten students in a class and the requirement is to find the typical value that gives the estimate of the weight of the whole class.

Students are *x*_{1}, *x*_{2}, *x*_{3}, *x*_{4}, *x*_{5}, *x*_{6}, *x*_{7}, *x*_{8}, *x*_{9} and *x*_{10} and their corresponding weights are *W*_{1}=50, *W*_{2}=59, *W*_{3}=65, *W*_{4}=60, *W*_{5}=55, *W*_{6}=63, *W*_{7}=69, *W*_{8}=70, *W*_{9}=63 and *W*_{10}=60kg.

**Solution**

Add up all the ten weight values.

**Sum of weight **= 614kg

**Number of student** = 10

**Average** = 614/10

**Average** = 61.4kg

61.4kg is the **typical value**.