Question

The following are the ages (years) of 5 people in a room:

14
,


16
,


16
,


13
,




A person enters the room.
The mean age of the 6 people is now 21.
What is the age of the person who entered the room?

Answer 1

67 years old. (you only gave 4 people and missed out one person)

Explanation:

take all the ages first and put the unknown (age of the person who entered the room) as x.

14, 16, 16, 13, x

all of these numbers added to together would be:

59 + x

Because the question is talking about the mean age, to find mean:

add all the values in the data (ages) and divide by the total number of values on the list. (in your case would be 6 people (following your question) but you gave only 5 people including the x).

then (59 + x) / 6 = 21

21 x 6 = 126

126 = 59 + x

x = 67