Education is critical to a democratic nation and in creating a strong economy (Verstegen, 2008). The importance of education is clear across society as an important tool in creating equal opportunities for all children regardless of race, ethnicity, and socioeconomic status. As school accountability increases, it is critical to determine what programs and resources have the biggest impact on student achievement so that policymakers and educators better understand how to allocate educational funding. This quantitative ex-post facto longitudinal study involved examining the relationship between socioeconomic status, per pupil expenditures, teacher attendance, salaries, education, retention, graduation rates, and student achievement at the high school level from 2017 through 2019. Student achievement was measured using the SAT score. A Pearson Product moment-correlation was calculated to analyze the degree and directional relationship between the variables. A positive correlation was noted across all three years between instructional expenditures per student and academic achievement. This analysis supports the research that additional educational funding leads to increases in student achievement. Unique to this research study was the addition of the split data sets by designating schools with 34% or more students as low-income and then analyzing the data across 3 years. The large discrepancy in the percentages of low-income students across districts prompted the split to better examine the relationship between low-income students on the various teacher and student factors. The findings highlight the negative correlation between low-income students with academic achievement, graduation rates and teacher retention. [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.]