EXHIBIT 3 JOINT FILING AGREEMENT The undersigned, Marshall Financial Group, Inc. and Dennis M. Mathisen, hereby agree that this Schedule 13D relating to securities of IPI, Inc. shall be filed on behalf of each of them. Dated: November 12, 1997...

                                   EXHIBIT 3


                             JOINT FILING AGREEMENT


    The undersigned, Xxxxxxxx Financial Group, Inc. and Xxxxxx X. Xxxxxxxx, 
hereby agree that this Schedule 13D relating to securities of IPI, Inc. shall 
be filed on behalf of each of them.

Dated: November 12, 1997
                                       XXXXXXXX FINANCIAL GROUP, INC.


                                       /s/ Xxxx X. Xxxxxxx
                                       ----------------------------------------
                                        By: Xxxx X. Xxxxxxx
                                        Its: Executive Vice President


                                       /s/ Xxxxxx X. Xxxxxxxx
                                       ----------------------------------------
                                       Xxxxxx X. Xxxxxxxx