mark was a muktihandicapped student needing special education. mark parnets and the school board signed ann agreement that required the board to pay the placement costs for mark at a residential school. the Bemedoctome school at the current annual rate of $30.000. The agreement required the board to pay for the next year 90 perecnt of any increase over the previous rate. The board was to pay no other costs for mark placemnet. Several months later. the board received an estimate of $62.487 for the nest year's cost at Benedictine for mark. The $62487 included the services of a one-to- one aide for mark during his waking hour. .The board refused to pay for the aide. In the proceeding that followed.Mark parents asserted that because the need for the aide was not anticipated when the agreemnet was signed. there was a mutual mistake of fact and the agreement was defective. Was it?