Three magnetic materials X , Y , and Z have magnetic...

For material $X$, $\chi = -0.004$. Since $-1 \le \chi < 0$, it is a diamagnetic material.

For material $Y$, $\chi = 2.4 \times 10^{-5}$. Since $0 < \chi < \varepsilon$ (a small positive number), it is a paramagnetic material.

For material $Z$, $\chi = 3000$. Since $\chi \gg 1$, it is a ferromagnetic material.

Thus, the correct sequence is Diamagnetic, Paramagnetic, Ferromagnetic.

Answer: Diamagnetic, Paramagnetic, Ferromagnetic