chapter-header

RS Aggarwal Solutions Class 9 Mathematics Solutions for Mean Median And Mode Of Ungrouped Data Exercise 18A in Chapter 18 - Mean Median And Mode Of Ungrouped Data

Question 23 Mean Median And Mode Of Ungrouped Data Exercise 18A

The mean weight of 25 students of a class is 52kg. If the mean weight of the first 13 students of the class is 48kg and that of the last 13 students is 55kg, find the weight of the 13th student.

Answer:

It is given that

Mean weight of 25 students = 52kg

So the total weight = 25 (52) = 1300kg

Mean weight of first 13 students = 48kg

So the total weight = 13 (48) = 624kg

Mean weight of last 13 students = 55kg

So the total weight = 13 (55) = 715kg

We know that

Weight of 13th student = total weight of the first 13 students + total weight of last 13 students – total weight of 25

students

By substituting the values

Weight of 13th student = 624 + 715 – 1300

On further calculation

Weight of 13th student = 39kg

Therefore, the weight of the 13th student is 39kg.

Video transcript
"hello students welcome to leader homework my name is anand anansharma the question here is the mean weight of 25 students of a class is 52 kg if the mean weight of first 13 students of the class is 48 kg and that of last 13 students is 55 kg find the weight of the 30th student so note down what all information is given to us mean weight of 25 students is given and that is 52 kg after that you can find out total weight total weight is equal to 52 that is mean into number of observation 25 and that will be 1300 kg now mean weight of first 13 students how much it is given 48 so here you can find total weight of first 13 students it will be 48 into 13 and that answer is around 624 kg and mean weight off last 13 students which is given 55 kg so total weight will be 715 kg now since we know how to find the weight of 30th student student there is a formula for this and that formula is first of all you need to add the total weight of first 13 and last 13 students weight of last 13 students minus total weight of 25 students so substitute all these values so 624 plus 715 minus 1300 and this answer will come up to 39 kg so the weight of 13th student is 39 kg that's all for this question if you have any queries feel free to comment below and subscribe to the channel for future updates thank you "
Connect with us on social media!
2022 © Quality Tutorials Pvt Ltd All rights reserved