Question 1

Initial estimates of the probabilities of events are known as _____.

Accepted Answer

A)  sets 
B)  posterior probabilities 
C)  conditional probabilities 
D)  prior probabilities 
A)  sets 
B)  posterior probabilities 
C)  conditional probabilities 
D)  prior probabilities

Question 2

Of the last 100 customers entering a computer shop, 25 have purchased a computer. If the relative frequency method for computing probability is used, the probability that the next customer will purchase a computer is _____.

Accepted Answer

A)  .25 
B)  .50 
C)  1 
D)  .75 
A)  .25 
B)  .50 
C)  1 
D)  .75

Question 3

If P(A) = .80, P(B) = .65, and P(A ? B) = .78, then P(B $\mid  $ A) = _____.

Accepted Answer

A)  .6700 
B)  .8375 
C)  .9750 
D)  Not enough information is given to answer this question. 
A)  .6700 
B)  .8375 
C)  .9750 
D)  Not enough information is given to answer this question.

Question 4

The probability of the occurrence of event A in an experiment is 1/3. If the experiment is performed two times and event A did not occur, then on the third trial event A _____.

Accepted Answer

A)  must occur 
B)  may occur 
C)  could not occur 
D)  has a 2/3 probability of occurring 
A)  must occur 
B)  may occur 
C)  could not occur 
D)  has a 2/3 probability of occurring

Question 5

The probability of the union of two events with nonzero probabilities _____.

Accepted Answer

A)  cannot be less than 1 
B)  cannot be 1 
C)  cannot be less than one and cannot be 1 
D)  None of the answers is correct. 
A)  cannot be less than 1 
B)  cannot be 1 
C)  cannot be less than one and cannot be 1 
D)  None of the answers is correct.

Question 6

On a December day, the probability of snow is .30. The probability of a "cold" day is .50. The probability of snow and a "cold" day is .15. Are snow and "cold" weather independent events?

Accepted Answer

A)  only if given that it snowed 
B)  no 
C)  yes 
D)  only when they are also mutually exclusive 
A)  only if given that it snowed 
B)  no 
C)  yes 
D)  only when they are also mutually exclusive

Question 7

If two events are independent, then _____.

Accepted Answer

A)  they must be mutually exclusive 
B)  the sum of their probabilities must be equal to 1 
C)  the probability of their intersection must be 0 
D)  None of the answers is correct. 
A)  they must be mutually exclusive 
B)  the sum of their probabilities must be equal to 1 
C)  the probability of their intersection must be 0 
D)  None of the answers is correct.

Question 8

A magician holds a standard deck of cards and draws one card. The probability of drawing the ace of diamonds is 1/52. What method of assigning probabilities was used?

Accepted Answer

A)  objective method 
B)  classical method 
C)  subjective method 
D)  experimental method 
A)  objective method 
B)  classical method 
C)  subjective method 
D)  experimental method

Question 9

Revised probabilities of events based on additional information are _____.

Accepted Answer

A)  joint probabilities 
B)  posterior probabilities 
C)  marginal probabilities 
D)  complementary probabilities 
A)  joint probabilities 
B)  posterior probabilities 
C)  marginal probabilities 
D)  complementary probabilities

Question 10

If X and Y are mutually exclusive events with P(X) = .295, P(Y) = .32, then P(X ∪ Y) = _____.

Accepted Answer

A)  .094 
B)  .615 
C)  1 
D)  0 
A)  .094 
B)  .615 
C)  1 
D)  0

Question 11

If P(A | B) = 0.3,

Accepted Answer

Question 12

Twenty percent of people at a company picnic got food poisoning. What percent of the people at the picnic did NOT get food poisoning?

Accepted Answer

A)  20% 
B)  40% 
C)  60% 
D)  80% 
A)  20% 
B)  40% 
C)  60% 
D)  80%

Question 13

A couple has three children. Assuming each child has an equal chance of being a boy or a girl, what is the probability that they have at least one girl?

Accepted Answer

A)  .125 
B)  .5 
C)  .875 
D)  1 
A)  .125 
B)  .5 
C)  .875 
D)  1

Question 14

Suppose we flip a fair coin five times and each time it lands heads up. The probability of landing heads up on the next flip is _____.

Accepted Answer

A)  1/2 
B)  1 
C)  0 
D)  None of the answers is correct. 
A)  1/2 
B)  1 
C)  0 
D)  None of the answers is correct.

Question 15

If two events are mutually exclusive, then the probability of their intersection _____.

Accepted Answer

A)  will be equal to 0 
B)  can have any value larger than 0 
C)  must be larger than zero, but less than 1 
D)  will be 1 
A)  will be equal to 0 
B)  can have any value larger than 0 
C)  must be larger than zero, but less than 1 
D)  will be 1

Question 16

Posterior probabilities are _____.

Accepted Answer

A)  simple probabilities 
B)  marginal probabilities 
C)  joint probabilities 
D)  conditional probabilities 
A)  simple probabilities 
B)  marginal probabilities 
C)  joint probabilities 
D)  conditional probabilities

Question 17

If A and B are independent events with P(A) = .38 and P(B) = .55, then P(A | B) =

Accepted Answer

A)  .209 
B)  0 
C)  .550 
D)  None of the answers is correct. 
A)  .209 
B)  0 
C)  .550 
D)  None of the answers is correct.

Question 18

The probability of an event is _____.

Accepted Answer

A)  the sum of the probabilities of the sample points in the event 
B)  the product of the probabilities of the sample points in the event 
C)  the minimum of the probabilities of the sample points in the event 
D)  the maximum of the probabilities of the sample points in the event 
A)  the sum of the probabilities of the sample points in the event 
B)  the product of the probabilities of the sample points in the event 
C)  the minimum of the probabilities of the sample points in the event 
D)  the maximum of the probabilities of the sample points in the event

Question 19

The collection of all possible sample points in an experiment is _____.

Accepted Answer

A)  the sample space 
B)  a sample point 
C)  an experiment 
D)  the population 
A)  the sample space 
B)  a sample point 
C)  an experiment 
D)  the population

Question 20

The probability of the intersection of two mutually exclusive events _____.

Accepted Answer

A)  can be any value between 0 and 1 
B)  must always be equal to 1 
C)  must always be equal to 0 
D)  can be any positive value 
A)  can be any value between 0 and 1 
B)  must always be equal to 1 
C)  must always be equal to 0 
D)  can be any positive value

Exam 4: Introduction to Probability

Initial estimates of the probabilities of events are known as _____.

Of the last 100 customers entering a computer shop, 25 have purchased a computer. If the relative frequency method for computing probability is used, the probability that the next customer will purchase a computer is _____.

If P(A) = .80, P(B) = .65, and P(A ? B) = .78, then P(B ∣\mid ∣ A) = _____.

The probability of the occurrence of event A in an experiment is 1/3. If the experiment is performed two times and event A did not occur, then on the third trial event A _____.

The probability of the union of two events with nonzero probabilities _____.

On a December day, the probability of snow is .30. The probability of a "cold" day is .50. The probability of snow and a "cold" day is .15. Are snow and "cold" weather independent events?

If two events are independent, then _____.

A magician holds a standard deck of cards and draws one card. The probability of drawing the ace of diamonds is 1/52. What method of assigning probabilities was used?

Revised probabilities of events based on additional information are _____.

If X and Y are mutually exclusive events with P(X) = .295, P(Y) = .32, then P(X ∪ Y) = _____.

If P(A | B) = 0.3,

Twenty percent of people at a company picnic got food poisoning. What percent of the people at the picnic did NOT get food poisoning?

A couple has three children. Assuming each child has an equal chance of being a boy or a girl, what is the probability that they have at least one girl?

Suppose we flip a fair coin five times and each time it lands heads up. The probability of landing heads up on the next flip is _____.

If two events are mutually exclusive, then the probability of their intersection _____.

Posterior probabilities are _____.

If A and B are independent events with P(A) = .38 and P(B) = .55, then P(A | B) =

The probability of an event is _____.

The collection of all possible sample points in an experiment is _____.

The probability of the intersection of two mutually exclusive events _____.

Data and Statistics

Descriptive Statistics: Tabular and Graphical Displays

Descriptive Statistics: Numerical Measures

Discrete Probability Distributions

Continuous Probability Distributions

Sampling and Sampling Distributions

Interval Estimation

Hypothesis Tests

Inference About Means and Proportions With Two Populations

Inferences About Population Variances

Tests of Goodness of Fit, Independence, and Multiple Proportions

Experimental Design and Analysis of Variance

Simple Linear Regression

Multiple Regression

Regression Analysis: Model Building

Time Series Analysis and Forecasting

Nonparametric Methods

Statistical Methods for Quality Control

Decision Analysis

Sample Survey

Filters

If P(A) = .80, P(B) = .65, and P(A ? B) = .78, then P(B $\mid$ A) = _____.