We start with the expression
\[
\left[\left(-\frac{5}{2} a^{2} b^{2}\right)^{3} \cdot\left(-\frac{5}{2} a^{2} b^{2}\right)^{7}\right]^{3}.
\]
Using the product of powers rule, we combine the exponents:
\[
\left(-\frac{5}{2} a^{2} b^{2}\right)^{3 + 7} = \left(-\frac{5}{2} a^{2} b^{2}\right)^{10}.
\]
Now applying the power of a power rule:
\[
\left(-\frac{5}{2} a^{2} b^{2}\right)^{10 \cdot 3} = \left(-\frac{5}{2} a^{2} b^{2}\right)^{30}.
\]
Step 2: Simplifying the Denominator
Next, we simplify the denominator:
\[
\left[\left(-\frac{5}{2} a^{2} b^{2}\right)^{4} \cdot\left(-\frac{5}{2} a^{2} b^{2}\right)^{3}\right]^{4}.
\]
Again, using the product of powers rule:
\[
\left(-\frac{5}{2} a^{2} b^{2}\right)^{4 + 3} = \left(-\frac{5}{2} a^{2} b^{2}\right)^{7}.
\]
Now applying the power of a power rule:
\[
\left(-\frac{5}{2} a^{2} b^{2}\right)^{7 \cdot 4} = \left(-\frac{5}{2} a^{2} b^{2}\right)^{28}.
\]
Step 3: Dividing the Expressions
Now we divide the simplified numerator by the simplified denominator:
\[
\frac{\left(-\frac{5}{2} a^{2} b^{2}\right)^{30}}{\left(-\frac{5}{2} a^{2} b^{2}\right)^{28}}.
\]
Using the quotient of powers rule:
\[
\left(-\frac{5}{2} a^{2} b^{2}\right)^{30 - 28} = \left(-\frac{5}{2} a^{2} b^{2}\right)^{2}.
\]
Step 4: Calculating the Final Result
Calculating the final expression:
\[
\left(-\frac{5}{2}\right)^{2} \cdot (a^{2})^{2} \cdot (b^{2})^{2} = \frac{25}{4} a^{4} b^{4}.
\]
Thus, the numerical value of the expression is \(100\) when evaluated, leading to the final result.