FCAT scores and poverty. In the state of Florida, elementaryschool performance is based on the average score obtained bystudents on a standardized exam, called the Florida ComprehensiveAssessment Test (FCAT). An analysis of the link between FCAT scoresand sociodemographic factors was published in the Journal ofEducational and Behavioral Statistics (Spring 2004). Data onaverage math and reading FCAT scores of third graders, as well asthe percentage of students below the poverty level, for a sample of22 Florida elementary schools are summarized by the number givenbelow. (x= percentage of students below poverty level, and y=mathscore ) n = 22 ??xi = 1292.7 ??yi = 3781.1 ??x2i =88668 ??yi2=651612 ??xiyi =218292 (a) Propose a straight-line model relatingmath-score to percentage of students below poverty level. (b) Findthe least-squares regression line fitting the model to the data.(c) Interpret the estimates for intercept and slope in the contextof the problem. (d) Test whether the math score is negativelyrelated to the percentage of students below the poverty level. (e)Construct a 99% confidence interval for the slope of the model, andinterpret your result in the context of the problem.
