the mean weight of 35 students in a class is 45kg . If the weight of class teacher is also included , the mean weight increase by 0.5 kg . Find the weight of class teacher
Answers
Given :
- The mean weight of 35 students in a class is 45kg.
- If the weight of class teacher is also included the mean weight increase by 0.5 kg.
To Find :
- Weight of class teacher.
Solution :
We have mean weight of 35 students as 45 kg.
We know the formula for mean.
Formula :
Mean = 45
Total number of observation → 35
Sum of observation = x
Block in the data in the formula,
Now, weight of a teacher is included in the mean. The mean weight increases by 0.5
•°• New mean weight = 45 + 0.5 = 45.5 kg.
The weight of 35 student was 45 kg. Since, the weight of teacher is added, the total number of observation which was 35 will now become 36.
Block in the data in the formula of mean,
The weight of the class teacher will be the difference between the sum of observation of weight of 35 students (1575) and the sum of the observation of weight of 35 students along with the teacher's weight (1638)
Class teacher's weight :
Given :-
- Mean weight of 35 students is 45kg.
- If weight of teacher is included, mean weight increases by 0.5kg.
To find :-
- Weight of teacher.
Solution :-
Case 1
- Mean weight of 35 students is 45kg
Case 2
- when teacher's weight is added, mean weight increases by 0.5
- New mean weight is 45 + 0.5 = 45.5
- total no. of people also increases by 36
_________________________
Weight of class teacher,
Total weight of 36 people - Total weight of 35 students
= 1638 - 1575
= 63kg
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