Write down some ways you have used probability within the last month. As you come in… Write down some ways you have used probability within the last month.

Section 2-1 Probabilities, Events, and Equally Likely Outcomes CLE 3126.5.1 Develop concepts in probability, including sample space and event probabilities

Vocabulary Probability: A number assigned to an outcome of an experiment expressing how likely that outcome is to occur Sample Space: Set of all possible outcomes of an experiment Event: A subset of a sample space

Event Practice A coin is flipped 3 times and the result is noted after each flip. Find the events: All heads Exactly 2 heads At least 2 heads

Event Practice A telephone sales representative makes successive calls to potential customers and the result of each call is noted. Calls which result in sales are noted as “S” and calls which result in no sale are noted as “N”. Calls are made until either 2 “no sale” calls are made or a total of 4 calls. Find the event E that exactly 1 sale is made. Find the event F that exactly 1 call results in no sale

Assignment of Probabilities Probability values can only be between 0 and 1 The probability of the sample space is 1 The probability of all outcomes need to add up to equal 1 The probability of an individual outcome is the weight

Assignment of Probability Practice A white-tailed deer population is found to have three classes: Adequately Nourished, Undernourished, and Extremely Undernourished. The number of undernourished deer outnumber the adequately nourished deer by 5 to 1. The extremely undernourished deer outnumber the adequately nourished deer by 4 to 1. Find the probability of finding one of each deer.

Probability of an Event The probability of an event, P(E) is defined to be the sum of the probabilities of the outcomes in E.

Probability of an Event Practice A customer telephone service lines records the lengths of call and classifies the calls based on length. The probability of a less than 1 minute call is .15. The probability of a call between 1 and 3 minutes is .25. The probability of a call between 3 and 5 minutes is .40. The probability of a call lasting more than 5 minutes is .20. Let E be the event that a call of length at least 1 minute is received. Find P(E)

Another Way What is another way we could have solved that problem? We could have subtracted the probability of a less than 1 minute call from 1. This is the complement! P(E) + P(E’) = 1

Classwork/Homework Work on p. 40 #1, 3, 4, 7, 8, 12, 23, 24, 26 #6, 11, 13 with work are Extra Credit (Do on separate page so that you can turn it in) We will have a Homework Quiz on Wednesday over ALL of 2.1