Information given in different groups or in different numbers is difficult to remember. In such cases, the approximate number is useful. That is why we often hear remarks such as, the average of dhone’s runs in five innings is 65, and in standard VI class of 65 pupils, and the average attendance last week was 60. Let us try to find out the mathematical meaning of the word `average’.

We know that the speed of a vehicle does not remain constant during a journey. There fore, the distance traveled is different in each hour. Still taking in to consideration the total distance traveled and total time required for that, the distance traveled by that vehicle per hour is determined for the sake of convenience. In order to find out the distance traveled in one hour, the total distance is divided by the total period, that is by total number of hours. The distance traveled in one hour is the average hourly speed of that vehicle.

For example, a car traveled a distance of 62 kilometers in the first hour, 55 kilometers in the second hour and 48 kilometers in the third hour. In this case, the total distance covered = 62 + 55+ 48= 165 kilometers.

Total time required = 3 hours.

165

Therefore, distance covered in one hour = ______ = 55 KMS

3

Learn points about average.

If the average of 10 numbers and the average of 4 numbers out of 10 are given and you are asked to find out the average of the remaining six, follow the following method.

Total distance

Average speed = ________________

Time

If a number equal to the average is added too group, their average remains the same.

When several numbers are given to find the average, add them all and divide the addition by the number of numbers i.e. if six different numbers are given, the addition of these six numbers will be, divided by 6 to get the average.