As college-bound high school seniors know, the ACT examination is possibly the single most important assessment students take during their academic careers. ACT scores can determine college entrance, scholarship dollars, and whether students will be placed in remedial courses. Parents pay large sums of money to prepare their children for this exam, and states use the scores as a metric to quantify the quality of schools and districts. Since 2015, all high school students in Arkansas take the ACT in the spring of their junior year. Given the significance of this exam, students, parents, and school personnel would benefit from knowing what factors could potentially predict ACT scores. This study measured the predictability of several factors on ACT subject area and Composite scores. The researcher used Multivariate General Linear Hypotheses to measure the predictability of gender, socio-economic status, eighth grade ACT Aspire scores (including Readiness scores), and the number of Pre-AP and AP courses taken on ACT subject area and Composite scores. The data indicated that the students' eighth grade ACT Aspire Composite score contributed most significantly to ACT score predictability. After the Aspire Composite scores, the number of Pre-AP and AP courses taken was the second greatest contributor to predictability. [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.]