The mean weight per student in a group of 7 students is 55 kg. The individual weights of 6 of them (in kg) are 52,54,55,53,56 and 54. Find the weight of the seventh student .

Explanation

Given
Mean weight per student in a group of `7` students if `55kg`
Mean weight of `7` students`=55kg`
No. of students `=7` Mean = sum of observations /No. of observations = sum of weights of `7` students /`7`
`55xx7`=sum of weights of `7` students
Sum of weights of `7` students=`385kg`
And given individual weights of `6` of them(in kg) are
`52,54,53,55,56 & 54`
Total weights of `6` students
`=52+54+55+53+56+54`
`=324 kg`
:. The weight of the seventh student=Total weights of `7` students`−`Total weights of `6` students
`=385−324`
`=61 kg`.
Hence the answer is `61kg`