The term ________ probability of A and B is used to denote the probability of the intersection of A and B.

marginal

conditional

joint

subjective

Which of the following best expresses the addition rule of probabilities?

P(AB) = P(A) + P(B)

P(AB) = P(A) + P(B) + P(AB)

P(AB) = P(A) + P(B) - P(AB)

None of the above

Which of the following would fit the definition of statistical independence of events A and B?

P(AB) = P(A) + A(B)

P(AB) = P(AB)/P(A)

P(AB) = P(A)

P(A and B) = P(A)

Which of the following demonstrates the multiplication rule?

P(AB) = P(A)P(B)

P(AB) = P(A)P(B)

P(AB) = P(AB)P(B)

P(AB) = P(AB)P(B)

A candy bowl contains 8 red M&Ms, 5 blue and 3 yellow. If 2 M&Ms are selected randomly, what is the probability that one will be blue and one will be yellow?

5 percent

20 percent

33.3 percent

12.5 percent

__________ probability is the proportion of times that an event will occur, assuming that all outcomes in a sample space are equally likely to occur.

Classical

Marginal

Joint

Subjective

If the outcome of event A is not affected by event B, then events A and B are said to be

mutually exclusive.

statistically independent.

collectively exhaustive.

None of the above

The collection of all possible events is called

a probability.

a sample space.

a joint probability.

the empty set.

The probability that house sales will increase in the next 6 months is estimated to be 0.25. The probability that the interest rates on housing loans will go up is estimated to be 0.7. The probability that house sales and interest rates will go up during the next 6 months is estimated to be 0.20.

The probability that house sales or interest rates increase during the next 6 months is _______.

0.75

0.85

0.705

0.90

The probability that house sales will increase in the next 6 months is estimated to be 0.25. The probability that the interest rates on housing loans will go up is estimated to be 0.7. The probability that house sales and interest rates will go up during the next 6 months is estimated to be 0.20.

The probability that house sales will go up given that the interest rates will increase during the next 6 months is _______.

0.11

0.195

0.2858

0.40

The probability that house sales will increase in the next 6 months is estimated to be 0.25. The probability that the interest rates on housing loans will go up is estimated to be 0.7. The probability that house sales and interest rates will go up during the next 6 months is estimated to be 0.20.

The probability of an increase in house sales and not an increase in interest rates is _______

.2

.05

.25

.5

The probability that house sales will increase in the next 6 months is estimated to be 0.25. The probability that the interest rates on housing loans will go up is estimated to be 0.7. The probability that house sales and interest rates will go up during the next 6 months is estimated to be 0.20.

The event of interest rates increasing and sales increasing are not statistically independent because

joint probabilities do not equal the product of the marginals.

the addition rule does not work here.

the marginal probabilities are all greater than .25.

None of the above

In the context of bivariate probabilities, the intersection probabilities,, are called marginal probabilities.

TrueFalse

The relative frequency probability is the limit of the proportion of times that event A occurs in a large number of trials,n.

TrueFalse

The odds in favor of a particular event are given by the ratio of the probability of the event divided by the probability of its complement.

TrueFalse

If E1, E2, ..., EKare collectively exhaustive events, the probability of their union is always smaller than 1.

TrueFalse

For conditional probabilities: P(AB) will always equal P(BA).

TrueFalse

When A and B are mutually exclusive, P(A or B) can be found by adding P(A) and P(B).

TrueFalse

If P(A) = 0.4 and P(BA) = 0.5, then there is a 20% chance that A and B occur at the same time.

TrueFalse

If P( AB ) = P( A ) P( B ), then A and B must be statistically independent.

TrueFalse

Suppose A and B are independent events where P(A) = 0.4 and P(B) = 0.5. Then P(AB) = 0.5.

TrueFalse

Suppose A and B are events where P(A) = 0.4, P(B) = 0.5, and P(AB) = 0.1. Then P(BA) = 0.5.

TrueFalse

If events A and B are mutually exclusive then they must be independent.

TrueFalse

Which of the following best describes the expected value of a discrete random variable?

It is the geometric average of all possible outcomes.

It is the weighted average over all possible outcomes.

It is the simple average of all possible outcomes.

None of the above

Which of the following is not a true statement about the binomial probability distribution?

Each outcome is independent of each other.

Each outcome can be classified as either success or failure.

The probability of success must be constant from trial to trial.

The random variable of interest is continuous.

A basketball player makes 80 percent of his free throws during the season. What is the probability that he will make exactly 6 of his next 8 free throws?

0.1468

0.3355

0.1678

0.2936

If n = 10 and= 0.8, then the mean of the binomial distribution is _______.

0.08

1.26

1.60

8.00

If n = 10 and= 0.8, then the standard deviation of the binomial distribution is ________.

0.80

1.26

1.60

8.00

If the outcomes of a discrete random variable follow a Poisson distribution, then their

mean equals the variance.

mean equals the standard deviation.

median equals the variance.

median equals the standard deviation.

The number of rainy days per month at a particular town follows a Poisson distribution with a mean value of 6 days. What is the probability that it will rain 4 days next month?

0.630

0.0273

0.1339

0.2125

When sampling without replacement from a finite population such that the probability of a success,, is no longer constant from trial to trial, the data follow a

binomial distribution.

uniform distribution.

Poisson distribution.

hypergeometric distribution.

The sum of the product of each value of a discrete random variable X times its probability is referred to as its

expected value.

variance.

mean.

Both (a) and (c)

The covariance of two random variables

does not have an upper or lower bound.

does not provide an indication of the direction of the relationship between the variables.

is greatly influenced by the scaling of the numbers.

both Answer #1 and Answer #3

All of the above.

The ______________ distribution can be used to approximate the binomial distribution when the number of trials is large and the probability of success is small (nP