Answer:
So for the first week, they sold 3701.
The second week was 1889 fewer, so take that from 3701 for the answer of 1812. So week two they sold 1812.
In the third week, they sold 273 more than the second week, meaning add 273 to 1812, and you get the answer 2085. So week three they sold 2085.
3701 + 1812 + 2085 = 7598
Hope this helps kiddo