Based on the given NMR spectrum, we can deduce the following information:1. A singlet at 1.9 ppm: This suggests that there is a group of protons in the molecule that are not coupled to any neighboring protons. This is often seen for methyl groups CH3 or other isolated protons.2. A quartet at 7.2 ppm with a J value of 8 Hz: This indicates that there is a group of protons that are coupled to three neighboring protons. The chemical shift of 7.2 ppm is characteristic of aromatic protons, and the coupling constant J value of 8 Hz suggests that these protons are in close proximity to the neighboring protons. This pattern is typical for a CH group on an aromatic ring that is adjacent to a CH3 group.Based on this information, the unknown compound X likely has an aromatic ring with a CH group adjacent to a CH3 group. A possible chemical structure for compound X is:`` CH3 | C--C ||| C--H``This structure represents an ethylbenzene derivative, where the CH3 group is directly attached to the aromatic ring. However, without more information, it is not possible to determine the exact structure or any additional substituents on the aromatic ring.