Mean is the average number in a set of data. To calculate mean, you add up all the numbers in a set of data and divide that sum by the amount of numbers you just added up. Example: numbers: 2, 2, 1, 3. 2+2+1+3=8.
You wear your wedding ring on the left hand, the finger next to your pinky finger. It is usually the third finger of the left hand, but there's no rule saying that it has to be that finger. In some parts of the world people wear it on their right hands, and in other parts of the world wedding rings are not worn at all.
The ring was then left on the ring finger. In a few European countries, the ring is worn on the left hand prior to marriage, then transferred to the right during the ceremony. For example, a Greek Orthodox bride wears the ring on the left hand prior to the ceremony, then moves it to the right hand after the wedding.