keeping in mind that a year has 12 months, thus 6 months is really 6/12 of a year.

Uh do you mean he earned $225 per week?
If yes, then he earned 45 per day.
The mean is 10,724.28.
Explanation:
The mean is all of the values divided by the number of values there are.
So what you have to do is add all of the numbers and divide it by the amount of numbers there are.
10,150+10,211+10,424+10,769+10,884+11,155+11,477= 75,070.
Since there are 7 numbers, divide 75,070/7 and you get your mean, which is 10,724.28 rounded.
Hope you could understand.
If you have any query, feel free to ask.