The relationship between family income and student achievement is powerful, and it's a notion to keep in mind when test scores become public. The "good" school systems tend to be located in areas where moms and dads know how to make a buck. Kids in the Park Hill School District do not arrive on waves of affluence, though. Nearly one in four receives a free or reduced-cost lunch. Still, student performance measures up with that of children in more chichi parts of town. During the 2008-09 school year, students at Park Hill's two high schools averaged 23.4 and 24 (out of 36) on their ACT tests, scores in line with the Blue Valley and Shawnee Mission districts. The numbers make raising children in southern Platte County look like a good bargain.