Explanation:
✧

Let the age of a person who entered the room be ' x '.
✧

- 14 , 14 , 18 , 18 , 22 , x
n ( number of observation ) = 6
x = 14 + 14 + 18 + 18 + 22 + x = 86 + x
Mean = 16
☯

~Plug the values :
⇢

~Apply cross product property :
⇢

⇢

Move 86 to right hand side and change it's sign
⇢

⇢


Hope I helped ! ツ
Have a wonderful day / night ! ♪
⋆ Let me know if you have any questions regarding my answer ⋆
!! ✎
▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁