Less than 50% of students from an inner-city high school in a southeastern US state who took the GATEWAY mathematics exam (2001-2007) earned a passing score on the first attempt, prompting teachers at the school to begin a summer intervention program based on Bandura's Self Efficacy Theory, to help them succeed on a subsequent reexamination. The program featured (a) extended learning time, (b) mastery learning, (c) direct instruction, (d) single-sex grouping, and (e) teacher collaboration. A survey of recent scholarly literature indicated that these 5 characteristics positively impact student learning and performance. The goal was to increase student understanding of fundamental mathematics concepts and by doing so increase their confidence in their ability to do well on standardized assessments. To test the efficacy of this intervention, this study used a quasi-experimental pre-post comparison group design to compare five academic indicators--GATEWAY exam scores, grade point averages, attendance, failed classes, and final averages in future mathematics courses--for students who participated in summer intervention programs (treatment group) with outcome data from students who did not participate (control group). A multivariate analysis of covariance (MANCOVA) was used to determine whether there was a significant difference in outcomes between students in the treatment and control groups. Findings revealed an overall significant effect of the summer intervention program on the five academic indicators (F = 5.024, p less than 0.001). Univariate F tests indicated that only student GATEWAY scores were affected by participation in the summer intervention program. This study contributes to social change by providing evidence that short-term intervention programs may help struggling students pass high stakes tests such as the GATEWAY examination. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]