Final answer:
A hydrophobic amino acid R group is typically found in the interior of a protein, away from the aqueous environment due to hydrophobic interactions.
Step-by-step explanation:
A hydrophobic amino acid R group (side group) would typically be found in the interior of a protein, especially in the case of soluble proteins. This is because hydrophobic (non-polar) amino acids tend to avoid water and hence aggregate towards the center of the protein away from the aqueous environment. On the other hand, hydrophilic (polar and charged) amino acids are more likely to be found on the surface of a protein where they can interact with the water in the environment. This categorization is largely due to the phenomenon known as hydrophobic interactions, where hydrophobic R groups of nonpolar amino acids aggregate together in the core of the protein, stabilizing its structure by avoiding contact with water.