• ### Unit 3: Probability

Penelope wants to be a lawyer and is trying to decide which of two colleges to attend. College A costs considerably more than College B, but a higher percentage of graduates of College A is accepted into the law school than the percentage of graduates of College B. Also, the prelaw curriculum is more difficult at College A than College B, so she might not have as competitive a GPA if she attends College A. Penelope is overwhelmed with the comparisons of cost, acceptance rates, and so forth, while trying to decide which college to attend.

While this is a personal decision for Penelope, her knowledge of probability theory will help her make the decision and be satisfied that she made the best decision for her unique circumstances.

Probability is everywhere, and you make decisions every day based on your own personal probabilities or on the probabilities calculated for you or by you. Should you drive in the rain and face a higher accident probability, or should you choose to wait until the rain subsides and risk being late for an important job interview? Should you buy a cheaper used car that might soon need repairs or a more expensive new car with an extended warranty? Should you enroll in an SAT prep course to improve your test scores?

The study of probability in Unit 3 will give you tools for understanding the use of probability theory in making both statistical and personal decisions. You will learn about sample spaces and mutually exclusive and independent events and how to calculate their probabilities.

The critical concept of conditional probability will also be addressed. You will put all of these concepts together to have a solid understanding of probability, and this foundation will provide you with the skills to use probability concepts later in the course and in life to help make sound decisions.

Completing this unit should take you approximately 11 hours.