ECON 2350 Stats TOPHAT Ch 5 homework questions

If P(A) = 0.35, P(B) = 0.45, and P(A and B) = 0.25, then P(A|B) is:

.25/.45=.556

Of the last 500 customers entering a supermarket, 50 have purchased a wireless phone. If the relative frequency approach for assigning probabilities is used, the probability that the next customer will purchase a wireless phone is

0.10

Suppose X = the number of cars owned by a family in the U.S. The probability distribution of X is shown in the table below. X........................0....................1...........2..........3 Probability.....0.56.......0.23......0.12.....0.09 What is the chance that a family owns more than one car? Express your answers as a decimal. Round your answers to the nearest 100th decimal points.

0.12+0.09 = .21

Suppose P(A) = 0.60, P(B) = 0.85, and A and B are independent. The probability of the complement of the event (A and B) is:

1 -(.6 ×.85) = .490

If P(A) = 0.25 and P(B) = 0.65, then P(A and B) is:

cannot be determined from the information given (need to know what P(A ⋂ B) is)

If A and B are mutually exclusive events with P(A) = 0.75, then P(B):

cannot be larger than 0.25

An approach of assigning probabilities which assumes that all outcomes of the experiment are equally likely is referred to as the:

classical approach

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

independent

The probability of the intersection of two events A and B is denoted by P(A and B) and is called the:

joint probability

Which of the following is equivalent to P(A|B)?

none of these choices: P(A and B) P(B|A) P(A)/P(B)