The mean weight of 75 2nd graders is 55.7 lbs and
the mean weight of 25 1st graders is 42.6 lb.
What is the mean weight of the 100 children
To find the mean weight of the 100 children, we need to calculate the total weight of all the children and then divide it by the total number of children.
Let's start by finding the total weight of the 2nd graders. The mean weight of the 2nd graders is given as 55.7 lbs, and there are 75 2nd graders. Therefore, the total weight of the 2nd graders is 55.7 lbs * 75 = 4177.5 lbs.
Next, let's find the total weight of the 1st graders. The mean weight of the 1st graders is given as 42.6 lbs, and there are 25 1st graders. Therefore, the total weight of the 1st graders is 42.6 lbs * 25 = 1065 lbs.
Now, we can find the total weight of all the children by adding the weights of the 2nd graders and the 1st graders: 4177.5 lbs + 1065 lbs = 5242.5 lbs.
Finally, to find the mean weight of the 100 children, we divide the total weight by the total number of children: 5242.5 lbs / 100 = 52.425 lbs.
Therefore, the mean weight of the 100 children is approximately 52.425 lbs.