The research discussed in this book uses multivariate methods to analyze the data; namely Structural Equation Modeling (SEM) besides multiple regression analysis. Two SEM models were formulated and their fit was tested using SPSS (Statistical Package for Social Scientists). One SEM model was found to have a better fit for the data i.e. covariance structure or correlation. With this SEM model it was found that the best causal relationship was between O-level Mathematics (OMATH) and dependent variables with physical science orientation, while O-level English (OENG) was found to have a causal relationship with dependent variables with social science orientation. OENG had more causal relationship with more dependent variables. The implication was, a good performance in social sciences was to a great extent due to previous good performance in OENG while a good performance in physical science was to a great extent due to previous good performance in OMATH. The study did not provide the probability of these. Thus, the study did in fact establish beyond any reasonable doubt that there is a causal relationship between o-level grades and performance in final year college examinations.