Statistics Chapter 5.1/5.2 Practice

Which two of the following statements describe a probability? a) It is always expressed as a percentage b) It describes the relative likelihood that an event will occur c) It is a number between 0 and 2 inclusive d) A probability lies between minus one and plus one

It describes the relative likelihood that an event will occur

Which of the following best describes the meaning of "outcome" in the context of a probability experiment? a) The expected result of the experiment. b) One and only one result of the experiment. c) Anything that can happen as a result of the experiment.

One and only one result of the experiment.

A cubic die with sides numbered 1 to 6 is rolled a large number of times. Which of these predictions can be made using the Law of Large Numbers? a) The number 3 will be uppermost about one sixth of the time. b) Even numbers will occur a large number of times. c) The number 2 will be uppermost more that 1/5th of the time.

The number 3 will be uppermost about one sixth of the time.

In a random experiment there are 8 possible outcomes, and two of them correspond to a favorable event. What is the classical probability of the event? a) 25% b) 1/10 c) 2/6 d) 20%

a) 25%

The value given for an Empirical Probability is based on: a) the past history of outcomes from the experiment b) someone's "best guess" based on his knowledge of the situation c) the ratio of favorable outcomes to possible outcomes to the experiment

the past history of outcomes from the experiment

The chance of drawing a spade from a deck of cards is 1/4. If the deck is shuffled between draws, what is the probability of drawing two spades in two draws? a) 1/2 b) 1/4 c) 2/16 d) 1/16

1/16

A bowl holds two white and three black marbles. Three marbles are selected randomly. What is the probability that all three are black? a) 4/30 b) 9/125 c) 3/5 d) 1/10

1/10

An event is nearly certain to occur if the probability of it occurring close to _______.

100%

Which of the following numbers could represent a probability that an event will occur? a) -0.3 b) 3/4 c) 1.2 d) 43

3/4

Jack wants to pack three different colored shirts for a trip. If he has seven colors to choose from, how many different selections of shirts can he make? a) 210 b) 70 c) 35 d) 21

35

When you roll a gaming die, the probability that the face with three dots will lie uppermost is 1/6. Use the complement rule to find the probability that the upper face will not be a three. a) 1/2 b) 1/3 c) 4/6 d) 5/6

5/6

An urn contains two red and three yellow balls. Two balls are selected randomly. What is the probability that both are yellow? a) 9/25 b) 6/25 c) 6/20 d) 1/4

6/20

When you flip three coins, the probability that they will show three "heads" is 1/8. What is the probability they will show 0, 1, or 2 heads? Hint: use the Complement rule. a) 7/8 b) 1/2 c) 5/8 d) 3/8

7/8

In a probability experiment, what is an outcome? a) The set of all possible results of the experiment. b) The result that was predicted beforehand. c) A particular result of the experiment.

A particular result of the experiment.

Which of the following is the best definition of "event" in the context of a probability experiment? a) A particular outcome of a random experiment b) The process of performing a random experiment c) A set of one or more outcomes of an experiment

A set of one or more outcomes of an experiment

Which of the following statements best describes the Law of Large Numbers? a) For a large number of trials, the empirical probability will approach the true probability. b) If you do an experiment a large number of times, the subjective probability will approach the classical probability. c) For a large number of observations the empirical probability will approach the subjective probability.

For a large number of trials, the empirical probability will approach the true probability.

How do you calculate classical probability? a) Number of actual outcomes divided by the number of possible outcomes. b) The number of favorable outcomes divided by the number of possible outcomes. c) The number of events divided by the number of possible outcomes.

The number of favorable outcomes divided by the number of possible outcomes.

Which of the following statements accurately repeats the formula P(B)=0.30? a) The probability that the event "B" will occur is thirty percent. b) P times B equals zero point three. c) The Bernoulli probability is 30%. d) The function "P" of the variable "B" equals 0.3.

The probability that the event "B" will occur is thirty percent.

A fair coin (that is, the probability of "heads" equals 50%) is flipped one thousand times. What does the Law of Large Numbers predict? a) The number of "heads" will be 500. b) The proportion of "heads" will be close to 1/2. c) Exactly half the trials will result in "tails".

a) The number of "heads" will be 500. b) The proportion of "heads" will be close to 1/2.

The equation P(A) = 1-P(~A) is known as the ________ Rule.

complement

Two coins are tossed and the results observed, what is an example of an event?

getting heads 4/5 times.

Two coins are tossed and the results observed. What is an example of an outcome?

getting one coin as "heads"

The formula P(~A) is read as "the probability of __________ A".

not

The Complement Rule tells us that P(A)+P(~A)= ___.

one

A random experiment consists of tossing two coins. Which of the following is not an event for this experiment. a) One coin comes up "heads". b) One of the coins is lost under the table. c) One coin comes up "heads" and the other "tails". d) Both coins come up "tails".

One of the coins is lost under the table.

An urn contains three black and two white beans. Which of the following experiments represents selection without replacement? a) Three beans are taken from the urn one at a time and their colors noted. b) Three beans are taken from the urn, their colors noted, then put back in the urn. c) A bean is selected, its color noted, and returned to the urn. This is done three times. d) Two beans are taken from the urn, then returned one at a time.

Three beans are taken from the urn one at a time and their colors noted.