Question

the mean weight of 9 students is 45 kg find their total weight and find the new mean weight if a student who weighs 50 kg joins them

Answer 1

new weight - 45+50÷10 # 54 kg

Answer 2

Mean weight of 9 students = 45 kg

Total weight of those 9 students = 45×9 kg = 405 kg

One new students joins them having weight 50 kg .

Then weight of all those 10 students = 405+50 kg = 455 kg

Mean = Total observation/No. of observation

Mean = 455 kg/10

Mean = 45.5 kg