4.2 Intro to Probability.pdf

Welcome to Gr 12 Data ManagementWEBSITE: seh.ycdsb.ca/teachers/aferguson/mdm4u1

MDM4U: Data ManagementClassroom ExpectationsAs a student in Ms. Ferguson's Data Management, the following is expected from me:1. I am expected to be punctual and in full uniform every day.2. I am expected to be respectful to my teacher and fellow students at all times.3. I am here to learn therefore I will not be using my cell phone or mp3 player during class.4. I am expected to have all the necessary items needed for math class (a calculator, a ruler, apencil, an eraser, lined and graph paper).5. I will be given a textbook, which I am expected to bring to class every day. I will also beexpected to access and print additional course materials from the website.6. I am expected to do my homework every day and constantly review my notes.7. If I am absent, I must bring a note from my parent/guardian.8. When I am absent, I am expected to go to the website and download the lesson(s) that Imissed and try the homework.9. If I am absent for a test, I will be expected to write it the day I return with a note from myparents, addressed to Ms. Ferguson, explaining the reason for the missed test.10. If I will miss a test because of a school related activity, I will speak to Ms. Ferguson prior tothe test day to reschedule when I will write the test.11. I will be required to use the classroom computers over the course of the semester. I will nottamper with these computers, as they are the only ones we have available.12. To receive notification of upcoming tests/quizzes/etc., text @mpm4u1b to (289) 278 ‐ 3129 tosubscribe. See website for more indepth instructions, or to subscribe via email.

Introduction to ProbabilityProbability is the branch of mathematics thatattempts to predict answers to hypotheticalquestions.We can generally only predict what might happen,which involves being able to calculate how likelyan event is.For example, though a weather report mayforecast a 90% chance of rain, there is still aslight possibility that sunny skies will prevail.While there are no sure answers, in this case itprobably will rain.

The probability of event A, P(A), is a quantifiedmeasure of the likelihood that the event willoccur.The probability of an event is always a valuebetween 0 and 1 (or 0 and 100%). It can beexpressed as a fraction, decimal or percent.A probability of 0 indicates that the event isimpossible, and 1 signifies that the event is acertainty.Vocabulary• Outcome ­ a possible result of a trial.• Event ­ a set of possible outcomes of anexperiment.• Simple Event ­ an event that consists of exactlyone outcome.

Theoretical ProbabilityTheoretical probability is the ratio of the number ofways an event can occur to the total number of possibleoutcomes.P(A) = n(A)n(S)where:­ n(S) is the collection of all possible outcomesof the experiment;­ n(A) is the collection of outcomes thatcorrespond to the event of interest.Given a large enough number of trials, the theoretical andexperimental probabilities should be equal.Ex 1.What is the probability of picking an ace from a deck ofcards?Ex 2.With two six­sided dice, what is the probability of rollinga) the sum of 8?b) a sum greater than 4?

The Complementary Event, A', consists of all the outcomes in thesample space that are not in set A. (Complementary events arethought of simply as the opposite of event A, the event of interest.)SAA'n(A) + n(A') = n(S)P(A) + P(A') = 1Ex 3.What is the probability of randomly picking a numberbetween 1 and 40 that is not a perfect square?Ex 4.There are several packets of gum, of different flavours, in abag. Eight are cherry­flavoured, 6 are sugarfreepeppermint,5 are sugarfree­cherry and some arepeppermint­flavoured. There is a 44% probability that arandomly selected packet is sugarfree. How manypeppermint­flavoured packets are there?

Homework:p 218­219 #1­14