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Question

All the students in a school were weighed, Their average weight was 31.4 Kilograms, and their total weight was 18,337.6 kilograms. How many students are in the school

Answer 1

Mean = average weight = total weight ÷ n, if n = number of students.

 

So 18,337.6 / n = 31.4   or   18,337.6 / n = 31.4 / 1. 

This is a proportion, and we will now invert (take reciprocals) of both sides, so we have n / 18,337.6 = 1 / 31.4;

we want to solve for n, so we now multiply both sides by that heavy weight.  Therefore

 

n = 18337.6 / 31.4 = 584.  I'm so glad that the answer is an integer.

 

Answer 2

Since the average is the ratio of the total weight to the number of students, you can solve this using the equation:

 

31.4 = 18337.6 / n,

 

where n is the number of students.

 

31.4 n = 18337.6 → n = 18337.6 / 31.4 = 584.

 

There are 584 students in the school.