The mean age of 5 people in a room is 40 years.
A person enters the room.
The mean age is now 37.
What is the age of the person who entered the room?
Answers
Mean = sum/number of observations.
Mean age of 5 people:
40 = (sum of ages of 5 people)/5
200 = sum of ages of 5 people
Let the age of new man be 'x'. Now,
Sum of ages = 200 + x
Number of ages(people) = 5 + 1 = 6
Mean = 37
=> (200 + x)/6 = 37
=> 200 + x = 222
=> x = 222 - 200
=> x = 22
Age of the person who entered the room is 22 year.
Answer:
Given :-
- The mean age of 5 people in a room is 40 years. A person enters the room. The mean age is now 37.
To Find :-
- What is the age of the person who entered the room.
Formula Used :-
Mean Formula :
Solution :-
First, we have to find the sum of observations age of 5 people in a room :
Given :
- Mean = 40
- Number of Observations = 5
According to the question by using the formula we,
By doing cross multiplication we get,
Now, we have to find the value of the age of the person who entered the room :
Let,
The age of people entered the room be y
Then,
Sum of Observations = 200 + y
Number of Observations of age of people :
Mean = 37
Given :
- Mean = 37
- Sum of Observations = 200 + y
- Total Number of Observations = 6
According to the question by using the formula we get,
By doing cross multiplication we get,
The age of people entered the room is 22 year.