DATA ANALYTICS EXAM 3 (pt. 2)

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:

70

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

0.0

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

1

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

1.00

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

This cannot be determined from the information given.

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

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

True

There are two types of random variables, they are:

discrete and continuous

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

independent

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

P(Ā) = 1 - P(A) is the:

rule of complements

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?

$93.50

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

True

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

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

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

True

Which of the following statements is true?

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