Question

Hi friends

Please answer me this question

The mean weight of a class of 38 students is 51kg. If the weight of a teacher be included, the mean increases by 400gms. Find the weight of a teacher.

Answer 1

hey buddy......❕❕❕

SOLUTION:::⏩⏩

⏺given: mean(m1)= 51,

no of students= 38

mean after teachers weight(m2)= 400..

we,, have,, m1= sum of WEIGHT of all students÷ no of students.let the total mass of all students be 'm'

51= m/38

m= 38×51= 1938..kg

then the weight of teacher=>>>

m2= m+ weight of teacher/ no of people..let the weight of teaCher be m'

51.4= 1938+ m'/ 38+1

51.4×39= 1938+m'

m'= 2004.6-1938= 66.6kg..

➖➖be brainlyyy➖➖➖

Answer 2

1)Mean weight of 38 students =51 Kg
No. of observations =38 students
Sum of observations =Mean*No. of observations (Since Mean =Sum of observations /No. of observations)
=51*38
=1,938
2)If teacher is included Mean is raised by 400 g
So Mean =51+400/1000=51+04=51.4Kg
No. of observations =38+1=39
Sum of observations =Mean*No. of observations (Since Mean =Sum of observations /No. of observations)
=51.4*39
=2,004.6
To know teachers weight we need to subtract sum of 39 observations -sum of 38 observations
=2004.6-1938
=66.6 Kg
Hence teacher's weight =66.6 Kg