For an ideal gas, the translational part of the internal energy \( E \) is related to the pressure \( P \) and volume \( V \) by the following equation:
\[
E = \frac{3}{2} n k_B T
\]
where:
- \( n \) is the number of moles,
- \( k_B \) is the Boltzmann constant,
- \( T \) is the temperature.
Using the ideal gas law:
\[
P V = n R T
\]
where \( R \) is the gas constant. From this, we get the relationship:
\[
E = \frac{3}{2} P V
\]
Thus, the correct answer is \( E = \frac{3{2} P V} \).