 Hello students, let's work out the following problem. It says in a class of 25 students 15 are boys. The mean weight of boys is 50 kg and that of the girls is 45 kg. Find the mean weight of the class. So let's now move on to the solution. Well given that number of boys is equal to 15 Let it be n1 and the number of girls The total number of students are 25 out of which 15 are boys. So there are 10 girls Let this be n2. We are given that mean weight of boys is denoted by x1 bar equal to 50 kg and the mean weight girls is given to be 45 kg Now the mean weight will be given by n1 into x1 bar plus n2 into x2 bar upon n1 plus and n2 As we know that the mean x bar is given by the formula summation f i x i upon Summation f i by the same logic here. We find the mean weight of the class here So we have 15 into 15 plus 10 into 45 upon n1 plus n2 and 1 plus n2 is equal to 25 we are given that total number of students are 25 This is equal to 750 plus 450 upon 25 and this is equal to 1200 upon 25 and this is equal to 48 kg so the mean weight denoted by x bar is equal to 48 kg Question and the session. Bye for now. Thank you. Have a good day