6.3 assignment of probabilities

6.3 Assignment of Probabilities

Example• A factory needs two raw

materials. The probability of not having an adequate supply of Material A is 0.05, whereas the probability of not having enough supply of Material B is 0.03. A study determines that the probability of a shortage od both is 0.01. What is the proportion of the time that the factory can operate?

Pr(short on A) = Pr(short on B) = Pr(short on both) =

6.3 Assignment of Probabilities

Example• The following table was

derived from a survey of college freshmen attending 4-year colleges. Each probability is the likelihood that a randomly selected freshman applied to the specific number of college.

• Convert these data into a probability distribution.

Number of Colleges Applied to Probability

1 0.17

2 or less 0.29

3 or less 0.43

4 or less 0.59

20 or less 1# of Colleges Applied to Probability

6.3 Assignment of Probabilities

Odds• If the odds in favor of an

event, E, occurring are: a to b

then

• If: Pr(E) = pthen the odds in favor of E are:

Example• Suppose that the odds of

rain tomorrow are 5 to 3. What is the probability it will rain?

Pr(E)a

a b

1

p

p

6.3 Assignment of Probabilities

ExampleIn poker, the probability of being dealt a hand containing a pair of jacks or better is about 1/6. What are the corresponding odds?

Example• The odds of Americans

living in the state where they were born is 17 to 8. What is the probability that an American selected at random lives in his or her birth state?

6.3 Assignment of Probabilities

ExampleThe probability of obtaining a sum of 8 or more when rolling two dice is 5/36.• What are the odds of

obtaining a sum of 8 or more?

Homework• Problems to complete from

section 6.3:– Pg. 281

#11 – 15 odd, 21, 22, 27, 28