The South Dakota Legislature established guidelines which courts must use to decide that a fair share of parental income and resources is allocated to the child when that child’s parents are separated, divorced or unmarried. The joint monthly net incomes of both parents must be used in determining the obligation and divided proportionately between the parents based on their respective net incomes, even if the parties have joint physical custody. The noncustodial parent’s proportionate share establishes the amount of the child support obligation.