Answer: 0.364
The reason that it would be 0.364 is because the thousandths place is the third decimal place, which would leave you with a 3 but since there is a 6 after the 3, the 3 would be rounded up to a 4.
The number that you are thinking of is 4. To get this answer I did the opposite of how you received your answer.
40 - 12 = 28
28 ÷ 4 = 7
The number that you are thinking of is 4.
It would be $44.8 I think