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The mean age of 5 people in a room is 26 years.
A person enters the room.
The mean age is now 33.
What is the age of the person who entered the room?
years

User Ylcnky
by
8.1k points

1 Answer

13 votes

Given:

The mean age of 5 people in a room is 26 years.

A person enters the room. The mean age is now 33.

To find:

The age of the person who entered the room.

Solution:

Formula for mean:


\text{Mean}=\frac{\text{Sum of observations}}{\text{Number of observations}}

The mean age of 5 people in a room is 26 years.


26=\frac{\text{Sum of ages of 5 people}}{5}


26* 5=\text{Sum of ages of 5 people}


130=\text{Sum of ages of 5 people}

The mean age is now 33. It means, the mean age of 6 people is 33.


33=\frac{\text{Sum of ages of 6 people}}{6}


33* 6=\text{Sum of ages of 6 people}


198=\text{Sum of ages of 6 people}

Now, the age of the person who entered the room is

Required age = Sum of ages of 6 people - Sum of ages of 5 people

=
198-130

=
68

Therefore, the age of the person who entered the room is 68 years.

User JoshieSimmons
by
8.3k points

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