Chapter 5 Probability

Probability

the proportion or fraction of times an outcome is likely to occur is referred to as

True

the relative frequency of an outcome is the probability of its occurrence.

1/6

-a gambler rolls a 3 with one role of a single fair dice. Given that the die was six-sided, what was the probability of rolling a 3 with one roll?

1. Random events 2. Random outcomes 3. random variables

-probability allows us to make predictions regarding:

Complementary outcomes

-the probabilities for two outcomes are complementary when the sum of their probabilities is equal to 1.00 p(A)+p(B)=1.00 -Likewise to find the probability for A p(A)=1-p(B) or p(B)=1-p(A) -(when two outcomes are complementary, subtracting 1 from the probability of one outcomes will give you the probability for the second outcome.

Conditional outcomes

-the probabilities for two outcomes are conditional when the probability of one outcomes is dependent on the occurrence of the other outcome. -an outcome is dependent when the probability of its occurrence is change by the occurrence of the other outcome. -(two outcomes are conditional when the occurrence of one outcome changes the probability that the other outcome will occur)

Independent outcomes

-the probabilities for two outcomes are independent when the probability of one out come does not affect the probability of the second outcome. p(A&B)=p(A)xp(B)

Mutually exclusive outcomes

-the probabilities for two outcomes are mutually exclusive when two outcomes cannot occur together. (or equal to zero) p(A&B)=0

the sample space

-the total number of possible outcomes for a random variable is referred to as:

the probability of the two outcomes occurring together is equal to zero (p=0)

-two outcomes are said to be mutually exclusive when:

1. Probability varies between 0 and 1 2. Probability can never be negative 3. Probability can be stated as a fraction or decimal. 4. Probability is most useful for describing fixed events Answer: 4

-which of the following is NOT a characteristic of probability?

Binomial probability distribution

a distribution of probabilities for random outcomes of a bivariate or dichotomous random variable is:

1. the proportion of times an outcome is likely to occur. 2. the fraction of times an outcome is likely to occur. 3. particularly useful for predicting the likelihood of random events

by definition, the probability of an outcome or even is