To find the product of \( \frac{21}{14} \) and \(-1.5\), we can first simplify \( \frac{21}{14} \).
\[ \frac{21}{14} = \frac{3}{2} \]
Now we multiply \( \frac{3}{2} \) by \(-1.5\):
\[ -1.5 = -\frac{3}{2} \]
Now, we can calculate:
\[ \frac{3}{2} \times -\frac{3}{2} = -\frac{9}{4} \]
To convert \(-\frac{9}{4}\) to a decimal:
\[ -\frac{9}{4} = -2.25 \]
Thus, the answer is:
\(-2.25\)