Answer:
The solubility of X in water at 17°C is 0.110 g/mL.
Explanation:
The water of a rock pool lined with mineral crystals is a saturated solution of said mineral, this means the concentration of X in those 36 mL is the solubility of compound X in water at 17 °C.
The dilution of the sample is not relevant, nor is that 500 mL volume. What's important is that 3.96 g of X form a saturated solution with 36.0 mL of water, so the solubility is: