Question

the mean weight of a class of 20 students is 48 kg. Two more students weighing 60 kg and 58 kg respectively join the class. What is the mean weight of the class now? ​

Answer 1

Mean weight of 20 students is 48 kg

So total weight of all students is 20 × 48 =960 kg

Now 2 students of 58 and 60 kg joined the class.

So now total weight of 22 students is 960 +58 +60 =1078

Now mean weight is 1078 ÷ 22 = 49 kg

Hope you got the answer.

Answer 2

mean weight of 20 students = 48

sum of weight of 20 students=48×20

=960

new mean = sum of 20 no.s+60+58/no of observations



=960+60+58/22

=1078/22

new mean =49

hope it helps you......