To find \( \ln 55 \) using the Product Rule of Logarithms, we can express 55 as the product of 11 and 5:
\[ \ln 55 = \ln (11 \times 5) \]
According to the Product Rule of Logarithms:
\[ \ln (a \times b) = \ln a + \ln b \]
Therefore:
\[ \ln 55 = \ln 11 + \ln 5 \]
Substituting the approximate values given:
\[ \ln 55 \approx 2.398 + 1.609 \]
Now, let's perform the addition:
\[ \ln 55 \approx 2.398 + 1.609 = 4.007 \]
Thus, the approximate value of \( \ln 55 \) is:
\[ \boxed{4.007} \]