Hi all,

I was going through the explanation in the book about weighted averages.I could not understand what the book is trying to say about this topic.

Can anyone help me out by answering my below questions:-

1)What is weighted averages?What I must know about this topic? Please give an example.

2)Question : In a translation problem, 40% of a student's grade comes from exams, 30% from written

assignments, 20% from conversational practice, and 10% from interpretation. If a

student's grades are 94 for exams, 88 for written assignments, 98 for conversational

practice, and 85 for interpretation, what is the student's overall grade in the course?

Answer is 92.1

Thank you in advance.

P.S.I tried hiding the answer by using the spoiler but it's still not working.Please help.

## Weighted Averages - Statistics

##### This topic has expert replies

- vk_vinayak
- Legendary Member
**Posts:**502**Joined:**03 Jun 2008**Thanked**: 99 times**Followed by:**21 members

Answer to the second question:

40% = 40/100 = 0.4,

similarly 30% = 30/100 = 0.3

(0.4)*(98) + (0.3)*(88) + (0.2)*(98) + (0.1)*(85)

=37.6 + 26.4 +19.6 + 8.5

=92.1

40% = 40/100 = 0.4,

similarly 30% = 30/100 = 0.3

(0.4)*(98) + (0.3)*(88) + (0.2)*(98) + (0.1)*(85)

=37.6 + 26.4 +19.6 + 8.5

=92.1

- VK

I will (Learn. Recognize. Apply)

I will (Learn. Recognize. Apply)

- anuprajan5
- Master | Next Rank: 500 Posts
**Posts:**279**Joined:**25 Jun 2012**Thanked**: 60 times**Followed by:**10 members

The effect/weightage of each section towards the final grade is:

40% of 94 on exams,

30% of 88 from written assignments,

20% of 98 for conversational practice,

10% of 85 from interpretation.

The total % add upto 100% (40+30+20+10)

When you calculate simple arithmetic mean, the weightage of each data point is equal towards the final average.

For example , arithmetic mean of 1,2,3,4 and 5 is 3. Each of these data points contribute evenly towards calculating the arithmetic mean. If you try to show it in weighted average terms, because there are 5 terms, the weightage for each data point is 20%.

Therefore, calculating by weighted average, 1*0.2 + 2*0.2 + 3* 0.2 + 4* 0.2 + 5*0.2 = 3.

In weighted averages some data points contribute more than others.

Regards

Anup

### GMAT/MBA Expert

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- GMAT Instructor
**Posts:**15463**Joined:**08 Dec 2008**Location:**Vancouver, BC**Thanked**: 5254 times**Followed by:**1266 members**GMAT Score:**770

We have a video that explains what weighted averages are and gives some examples: https://www.gmatprepnow.com/module/gmat- ... ics?id=805shanice wrote: 1)What is weighted averages?What I must know about this topic? Please give an example.

Once you're more familiar with the concepts, you can tackle these questions:

https://www.beatthegmat.com/weighted-ave ... 14506.html

https://www.beatthegmat.com/weighted-ave ... 17237.html

https://www.beatthegmat.com/average-weig ... 57853.html

https://www.beatthegmat.com/averages-que ... 87118.html

Cheers,

Brent