Answer:
The original number was 54.5.
Step-by-step explanation:
If a number is increased by 2.8%, then it is 102.8% of it's original number.
In mathematics, "of" in virtually all cases means "multiplied by".
Therefore, we do the opposite:
1. Convert to a decimal.
102.8% = 1.028
2. Divide by the decimal.
3. Round it to the nearest tenth.
54.47 rounds to 54.5.