This mixed-methods study investigated the impact of the Foundations of Mathematical Reasoning course within the Quantitative Reasoning Pathway developed by the Dana Center for Mathematics Pathways at the University of Texas at Austin on student motivation in mathematics. Quantitative research was conducted to determine the effects of the Foundations of Mathematical Reasoning course, which is part of the Quantitative Reasoning Pathway curriculum, on student mathematics motivation over time. These effects were compared with those of the traditional Algebra II course. The influence of gender identity on motivation scores in these courses was also examined quantitatively. Qualitative data were collected to assess the students' perceptions of the relevance of course content and its connection to opportunities beyond high school. Statistically significant quantitative results indicate students participating in the Foundations of Mathematical Reasoning course experienced an increase in self-efficacy and a decrease in test anxiety. Moreover, among women students in the experimental group, intrinsic motivation, self-efficacy, and utility value showed significant increases and test anxiety was even further reduced. Qualitative analysis reveals students in the experimental group--those who took Foundations of Mathematical Reasoning--found relevance in course content such as budgeting, graphical analysis, and credit card fluency, recognizing its concrete connections to their current and future lives. Conversely, students in the control group--those who took Algebra II--perceived the relevance of the course content primarily in terms of assessment performance and course completion expectations. When considering the relevance of course content to post-high school opportunities, both groups emphasized the importance of the interconnectedness of math and postsecondary success. However, students in the experimental group demonstrated clearer connections between course content and their future aspirations, while uncertainty regarding the applicability of their learning persisted among students in the control group. These findings underscore the significance of curriculum design in fostering student motivation and the importance of real-world relevance in mathematics education. [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.]