Answer:
The age of the person who walked in the room is 44.
Explanation:
The original mean age is 38 which means the total ages combined divided by the 5 people.
5 people x 38 (the mean age) = x
x = Total ages combined
x = 190 years old
Then another person came in, now totaling 6 people, and the mean age changed to 39 years old, an increase.
6 people x 39 (the new mean age) = y
y = Total ages combined
y = 234 years old
So, we are trying to figure out the age of the new person who came in. We have to subtract the new total age (y) by the original total age (x).
y - x = Age of new person in room
234 years old - 190 years old =
44 years old