Data test 3

If A and B are any two events with P(A) = .8 and P(B|A) = .4, then the joint probability of A and B is:

0.32

If A and B are mutually exclusive events with P(A) = 0.30 and P(B) = 0.40, then the probability that either A or B occur is:

0.70

The probability of an event and the probability of its complement always sum to:

1

Suppose that 18% of the employees of a given corporation engage in physical exercise activities during the lunch hour. Moreover, assume that 57% of all employees are male, and 12% of all employees are males who engage in physical exercise activities during the lunch hour. Round your answers to two decimal places, if necessary. A) If you choose an employee at random from this corporation, what is the probability that this person is a female who engages in physical exercise activities during the lunch hour? B)If you choose an employee at random from this corporation, what is the probability that this person is a female who does not engage in physical exercise activities during the lunch hour?

A) 0.06 B) 0.37

Starting with $100 in your pocket, you place two bets. On the first bet, you either win $25, with probability 0.6, or lose $30, with probability 0.4. On the second bet, you either win $50, with probability 0.3, or lose $35, with probability 0.7. Which of the following is closest to the mean amount of money you have in your pocket after the two bets?

b. $93.50

A random variable X has the following probability distribution: P(X = 1) = P(X = 10) = 0.025, P(X = 2) = P(X = 9) = 0.05, P(X = 3) = P(X = 8) = 0.1, P(X = 4) = P(X = 7) = 0.15, P(X = 5) = P(X = 6) = 0.175. Which of the following is equal (to three decimals) to the probability that X is greater than the mean of X plus the standard deviation of X, i.e., that X is more than one standard deviation to the right of the mean?

c. 0.175

There are two types of random variables, they are:

discrete and continuous

Conditional probability is the probability that an event will occur, with no other events taken into consideration.

false

If A and B are independent events with P(A) = 0.40 and P(B) = 0.50, then P(A/B) is 0.50.

false

If A and B are two independent events with P(A) = 0.20 and P(B) = 0.60, then P(A and B) = 0.80.

false

If events A and B have nonzero probabilities, then they can be both independent and mutually exclusive.

false

The number of cars produced by GM during a given quarter is a continuous random variable.

false

If P(A) = P(A|B), then events A and B are said to be:

independent

Probabilities that can be estimated from long-run relative frequencies of events are called:

objective probabilities

A function that associates a numerical value with each possible outcome of an uncertain event is called a:

random variable

P(Ā) = 1 - P(A) is the:

rule of comlements

Probabilities that cannot be estimated from long-run relative frequencies of events are called:

subjective probabilities

A random variable is a function that associates a numerical value with each possible outcome of a random phenomenon.

true

Suppose A and B are mutually exclusive events where P(A) = 0.2 and P(B) = 0.5, then P(A or B) = 0.70.

true

The number of car insurance policy holders is an example of a discrete random variable.

true

The number of people entering a shopping mall on a given day is an example of a discrete random variable.

true

The temperature of the room in which you are writing this test is a continuous random variable.

true

The time students spend in a computer lab during one day is an example of a continuous random variable.

true

Two events are said to be independent when knowledge of one event is of no value when assessing the probability of the other.

true

Two or more events are said to be exhaustive if one of them must occur.

true

You play a game where the amount you win (or lose, if negative) can be $1,000, $100, $0, or -$2,000. Let X be the amount you win (or lose), and assume the distribution of X is the following: P(X = 1,000) = 0.1, P(X = 100) = 0.5, P(X = 0) = 0.2, and P(X = -2,000) = 0.2. Which of the following is true (to the nearest dollar)?

. Mean of X = -$250, Standard deviation of X = $918

If events A and B are mutually exclusive, then the probability of both events occurring simultaneously is equal to:

0.0

If two events are collectively exhaustive, what is the probability that one or the other occurs?

1.00

Let A and B be the events of the FDA approving and rejecting a new drug to treat hypertension, respectively. The events A and B are:

Mutually exclusive

Which of the following statements is true?

The sum of all probabilities for a random variable must be equal to 1.

If two events are independent, what is the probability that they both occur?

This cannot be determined from the information given.