Weighted Average

It is actually quite simple to find the average we all know from our school mathematics. Let’s say we have 10 numbers, then we add them all up and divide the sum with the number of numbers, in this case 10, and we have the average.

When is weighted average, the difference is only that at least one of the 10 numbers is given a different weight compared to the rest, let’s say that is 2. That means that this number count double compared to the other 9 numbers? So our calculation will be that number times 2 + the other 9 numbers, divided 2 + 9.

The idea of weighted average is not difficult to understand. This is extremely simple.

One example , Suppose that there are two classes. One is for boys having strength of 12 and the other is for girls which has 6 students in it. If there takes place an exam, and the scores of boys are 8, 6, 7, 4, 9, 5, 8, 2, 7, 6, 5, 7. Now calculate the average score of boys and you will find that the average score per boy is (8+6+7+4+9+5+8+2+7+6+5+7)/12= 6.17. Now turn towards the girls, the girls scored 8, 9, 7, 9, 10, 6. Now calculating the average score for girls we find that girls maintained an average of above (8+9+7+9+10+6)/6=8.0. Now we calculate the cumulative average of both the classes it comes to just above ( by adding the two averages and then dividing by 2. the result is(6.17+8.0)/2= 7.085 ). This is where the average differs from the weighted average. However, many people will not like the results since these provide a misleading picture of the performance of the students since the average of the majority of students, the boys, is much less than the aggregate average. In this case a pragmatic assessment maker shall try to bring theory close to the reality. He shall assign a weightage to each class. He will multiply the average of boys by their strength, i.e. 12, and multiply the average score of girls by the strength of their section, i.e. 6 and add the two products of multiplications and then divide the sum of these products by the sum of the weightages that he assigned to the individual averages. [ {12(6.17) + 6(8.17)} / 12+6]= 6.78. If you calculate the answer now, it’s a lot different.

Another example is, in 2 regions the average weight of people is 150 and 140. Utilizing this type of Information, we simply cannot obtain the unique average weight with regards to people inside the two parts bundled.

This enable me set up this type of technique. With section 1 there are actually 40 men and women, and the average bodyweight happens to be 150 and additionally inside of segment 2 you’ll encounter 50 persons, and their unique average bodyweight is actually 140. Acquiring this exact 2 groups the weighted average calculations shall be along these lines: 40 * 150 + 50 * 140 / 40 + 50 = 144.4 
So, we’re able to obtain the average weight of folks inside of each groups, which is equal to 144.4.

http://weightedaverage.org/