This study evaluated student preparation for a course in calculus for business, management, and social sciences as a prerequisite for success in probability theory. The study included a review of the literature, development of an assessment instrument and cut-off scores, and review and validation of the study criteria, the assessment instrument, and the cut-off scores. A 33-item questionnaire was administered during the 1997 spring semester to 20 students enrolled in a probability theory course at Orange Coast College (California). The students had completed a course in calculus for business, management, and social sciences. Results of the study indicated that although students showed weakness in four instructional objectives: implicit differentiation, calculus applications to probability, numerical techniques, and proof construction, they nevertheless were deemed adequately prepared for the probability theory course. Appended are calculus course instructional objectives, the proficiency criteria developed, a diagnostic student assessment examination in calculus, and a data/assessment results table. (Contains 54 references.) (JLS)