The table below shows children in a class sorted according to their weights.
The mean weight is calculated as 26 kilograms. How many children have weights between 23 and 25 kilograms?
Given: mean weight = 26 Kg
Let the unknown weight is x.
Mean age of child = Total age/ total number of children
⇒ 560 + 24x = 26(21 + x)
⇒ 560 + 24x = 546 + 26x
⇒ 560 - 546 = 26x – 24x
⇒ 14 = 2x
⇒ x = 7
children have weights between 23 and 25 kilograms = 7
Total number of questions = 12
How much each question will cost?
4