The purpose of this study was to investigate and identify possible relationships between academic achievement, as measured by high school graduation rate and ACT composite scores of individual school districts within the state of Tennessee, and the per-pupil expenditure of each district. Research was conducted to determine whether a significant difference existed in academic achievement measures (high school graduation rate, ACT composite score) among school districts in the state of Tennessee that were classified as above average, average, and below average in relation to their per-pupil expenditure (PPE) in the 2013-2014, 2014-2015, and 2015-16 school years. "Ex post facto" data were collected from the Tennessee Department of Education website. All pertinent school district information reported appeared on the Tennessee State Report Card website. This publicly reported and available data were collected by accessing the Tennessee State Report Card website. The researcher recorded data related to each school district that reported data in all three of the following categories: per-pupil expenditure, graduation rates, and ACT composite scores. This study examined the relationship of graduation rates to per-pupil expenditure in the 2013-2014, 2014-2015, and 2015-2016 school years. The results indicated that the high school graduation rates during the 2013-2014 and 2014-2015 school year were not significantly affected by per-pupil expenditure. However, significance was found regarding high school graduation rates in the 2015-2016 school year (p = 0.016). There was a significant difference in the means between the bottom-third (93.537%) and the top-third (90.422%) of per-pupil expenditure levels during the 2015-2016 school year, with the top-third having significantly higher graduation rates. This study also examined the relationship of ACT composite score to per-pupil expenditures in the 2013-2014, 2014-2015, and 2015-2016 school years. The results for all of the research questions indicated that the ACT composite score during all years was not significantly affected by per-pupil expenditure. [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://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]