Density problems (work check)

Here's a question I was working on:

A crystal of sulfur has a density of 1.94 g/cc.

(a) What is the mass (in grams) of a sulfur crystal with a volume of 2.534 cm3?

(b) What is the density of sulfur in kg/m3?

(c) What is the volume (in mL) of a sulfur crystal that weighs 9800 mg?

Here is the solutions I've arrived at:

(a) Well we know thus rearrange as to obtain the value of which I rounded to as taking into account significant digits.

Correct or incorrect?

(b) I know thus I can write

I'm not so sure about the sig figs on that final answer there, or if it's even the correct conversion at all?

(c) I rearrange as such: and plugged in

Is this correct?

If you could help me with the mistakes I made and offer advice, etc. that would be appreciated. Thanks a lot for reading. :)