 Hello and welcome to the session. In this session we discuss the following question which says find the fourth proportional to the numbers 9, 36 and 3. We know that if A is to B is proportional to C is to D then D is the fourth proportional to A, B and C and also the product of extremes that is A multiplied by D is equal to the product of means which is B multiplied by C. This is the key idea to be used in this question. Now we move on to the solution. We need to find out the fourth proportional so we assume that the fourth proportional to the numbers 9, 36 and 3 Bx then we have 9 is to 36 is proportional to 3 is to x. So this means the product of extremes that is 9 into x is equal to product of the means that is 36 into 3 or you can say we get x is equal to 36 into 3 upon 9. Now 9 four times is 36 so this is equal to 4 multiplied by 3 so we get x is equal to 12 that is the fourth proportional to the numbers 9, 36 and 3 is 12. So this completes the session. Hope you have understood the solution for this question.