Multiply −9 1/2

To solve the multiplication of \(-9 \frac{1}{2}\) by \(0.04\):

First, convert \(-9 \frac{1}{2}\) to an improper fraction:
\[
-9 \frac{1}{2} = -\frac{19}{2}
\]

Now, multiply \(-\frac{19}{2}\) by \(0.04\):
\[
0.04 = \frac{4}{100} = \frac{1}{25}
\]

Now perform the multiplication:
\[
-\frac{19}{2} \times \frac{1}{25} = -\frac{19 \cdot 1}{2 \cdot 25} = -\frac{19}{50}
\]

Now, convert \(-\frac{19}{50}\) to a decimal by performing the division:
\[
-19 \div 50 = -0.38
\]

Thus, the final answer is:
\[
\boxed{-0.38}
\]

So the correct response is \(-0.38\) (negative 0.38).