Question

The mean weight of a group of 15 boys is 65 kg . one boy joins the group and his weight is 45 kg . what is the average weight of all the boys

I need the answer within 2 to 3 days!​

Answer 1

The new average is

63.75kg

Explanation:

We have 15 boys with avg. weight of 65kg. That means that the sum of their weights is:

15*65kg = 975kg

We add a boy weighing 45kg. The new sum is

975kg + 45kg = 1020kg

To get the new average, we need to divide by the number of boys. It's no longer 15, because we've added one. It's now 16

avg_weight = 1020kg / 16 = 63.75kg