How is octal converted to hex here?

Octal to binary (3 bits each), then regroup in 4 bits

Octal to decimal by division only

Each octal digit equals a hex digit

How are bits grouped around the binary point?

In 4s from the point, padding 0s at the ends

Short answer

Convert octal 430.25 to binary as 100011000.010101, regroup bits in fours from the point: 0001 0001 1000 . 0101 0100, giving hex 118.54.

Convert (430.25)₈ = (?)₁₆.

Convert octal to binary (3 bits per digit), then regroup the bits in 4s from the binary point (pad with 0s at the ends) to get hex.

Step 1: Octal to binary

Octal	4	3	0	.	2	5
Binary	100	011	000	.	010	101

$(430.25)_8 = (100011000.010101)_2$

Step 2: Group in 4 bits

Groups	0001	0001	1000	.	0101	0100
Hex	1	1	8	.	5	4

Check: $(430.25)_8 = 280.328125_{10}$ and $(118.54)_{16} = 280 + \frac{5}{16} + \frac{4}{256} = 280.328125$ .

Answer: $(430.25)_8 = (118.54)_{16}$

✓ Answer checked by Claude Opus 5.5 (high effort)