Question

Mean weight of a class of 20 students is 48 kg , if two more students of weight 60 kg and 50 kg respectively join the class what is the mean weight of class now?

Answer 1

Find the sum of the weight of the 20 students:

Mean Weight = 48 kg

Total Weight = 20 x 48 = 960 kg

Find the weight of the 22 students:

One student = 60 kg

Other students = 50 kg

Total Weight = 960 + 60 + 50 = 1070 kg

Find the mean weight of the class now:

Mean Weight = 1070 ÷ 22 = 48.64 kg

Answer: The mean weight of the class now is  48.64 kg

Answer 2

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