The random numbers represent a sequence of digits where they appear in a perfectly random order. Selection of a random number from a table of random numbers has the same probability of selection. There are various metilods to generate random numbers. Also there are tables of random numbers. Briefly we illustrate the use of random numbers. Let us consider the following two digits random numbers :

23, 04, 82, 07, 14, 66, 54, 10, 72 and 32.

Suppose we have marks of a subject of 100 students and we want to draw a sample of marks of size 10. To draw this, number the students from 00 to 99 and using the above random numbers select the marks of a student whose number is 23 since the first random is 23. Next select a student whose number is 04 since the next random number is 04. Repeating this process we obtain a sample of marks of size 10.

By considering another set of 10 random numbers, we can construct another sample of marks of size 1 0 and so on.