 Hello and welcome to this session. In this session we discussed the following question which says, find the mean proportional between 4 and 25. Now if we have A is to B is proportional to B is to C then the product of extremes A multiplied by C is equal to product of means that is B multiplied by B or we can say that B square is equal to AC or B is equal to square root AC and this B is called the mean proportional. This is the key idea to be used in this question. Now we proceed on to its solution. Now we assume let the mean proportional between 4 and 25 be equal to X then this means that 4 is to X is proportional to X is to 25. So now the product of extremes 4 multiplied by 25 is equal to product of the means that is X multiplied by X which is X square. So we have X square is equal to 100 which means that X is equal to 10 thus we have the mean proportional between 4 and 25 is 10. So this is our final answer. This completes this session. Hope you have understood the solution for this question.