Answer:
$247
Step-by-step explanation:
It depends.
Most months, you will earn $1900, so your budget will be ...
... 12% × $1900 = $228.
In one month out of 6, you will earn $2850, so your budget can be ...
... 12% × $2850 = $342.
_____
If you average out your earnings over 6 months, and compute your budget on that basis, then your monthly grocery budget is ...
... ($950 × 13)/6 × 12% = $247
