To solve the given integral, we need to use the definition of the function \( f(x) \) and then substitute it into the integral. We will use numerical integration to evaluate the integral.
Step 1: Define the Function \( f(x) \)
Given the function:
\[ f(x) = \int_{1}^{x} \sqrt{1 + t^3} \, dt \]
Step 2: Define the Integrand
We need to evaluate the integral:
\[ \int_{0}^{1} x f(x) \, dx \]
Step 3: Evaluate the Integral
Using numerical integration, we find:
\[ \int_{0}^{1} x f(x) \, dx \approx -0.2032 \]