Liability of guardians, trustees and agents: representatives bear equivalent tax, interest and penalty obligations for incapacitated principals. Where a business liable to tax, interest or penalty is carried on by a guardian, trustee or agent on behalf of a minor or other incapacitated person, the tax, interest or penalty shall be levied upon and recoverable from such guardian, trustee or agent in like manner and to the same extent as it would be determined and recoverable from the minor or incapacitated person, as if the person were a major or capacitated person conducting the business himself, and all provisions of the Act and rules apply accordingly.