Representative Values
You might be aware of the term average and would have come across statements involving the term ‘average’ in your day-to-day life:
1. Isha spends on an average of about 5 hours daily for her studies.
2. The average temperature at this time of the year is about 40 degree celsius.
3. The average age of pupils in my class is 12 years.
4. The average attendance of students in a school during its final examination was 98 per cent.
Many more of such statements could be there. Think about the statements given above.
Do you think that the child in the first statement studies exactly for 5 hours daily? Or, is the temperature of the given place during that particular time always 40 degrees? Or, is the age of each pupil in that class 12 years? Obviously not.
Then what do these statements tell you?
By average we understand that Isha, usually, studies for 5 hours. On some days, she may study for less number of hours and on the other days she may study longer.
Similarly, the average temperature of 40 degree celsius, means that, very often, the temperature at this time of the year is around 40 degree celsius. Sometimes, it may be less than 40 degree celsius and at other times, it may be more than 40°C.
Thus, we realise that average is a number that represents or shows the central tendency of a group of observations or data. Since average lies between the highest and the lowest value of the given data so, we say average is a measure of the central tendency of the group of data. Different forms of data need different forms of representative or central value to describe it. One of these representative values is the
You will learn about the other representative values in the later part of the chapter.