Deck 11: Probability and Statistics

Question 1

Deterministic techniques assume that no uncertainty exists in model parameters.

Answer 1

True

Question 2

A set of events is collectively exhaustive when it includes all the events that can occur in an experiment.

Answer 2

True

Question 3

Seventy-two percent of all observations fall within one standard deviation of the mean if the data is normally distributed.

Answer 3

False

Question 4

Relative frequency is the more widely used definition of objective probability.

Question 5

A conditional probability is the probability that an event occurs given that another event has already occurred.

Question 6

A succession of events that does not affect other events is independent.

Question 7

A continuous random variable may assume only integer values within a given interval.

Question 8

Probability trees are used only to compute conditional probabilities.

Question 9

A joint probability is the probability that two or more events that are mutually exclusive can occur simultaneously.

Question 10

A marginal probability is the probability of a single event occurring.

Question 11

Objective probabilities that are stated after the outcomes of an event have been observed are relative frequencies.

Question 12

An experiment is an activity that results in one of several possible outcomes.

Question 13

Objective probabilities that can be stated prior to the occurrence of an event are classical or a priori.

Question 14

Probabilistic techniques assume that no uncertainty exists in model parameters.

Question 15

Subjective probability is an estimate based on personal belief, experience, or knowledge of a situation.

Question 16

The events in an experiment are mutually exclusive if only one can occur at a time.

Question 17

A Venn diagram visually displays mutually exclusive and non-mutually exclusive events.

Question 18

Conditional probabilities are shown in Venn diagrams.

Question 19

In a given experiment, the probabilities of all mutually exclusive events sum to one.

Question 20

A binomial probability distribution indicates the probability of r successes in n trials.

Question 21

The expected value of a random variable is computed by multiplying the sum of each possible value of the variable by the probability of that random variable.

Question 22

The fact that the first toss of a coin has no effect on the outcome of the second toss of the coin suggests that these events are ________.

Question 23

In Bayesian analysis, additional information is used to alter the conditional probability of the occurence of an event.

Question 24

The expected value of a discrete random variable is greater than or equal to zero.

Question 25

A normally distributed random variable has a mean of zero and a standard deviation of one.

Question 26

The variance of a random variable is computed by multiplying each possible value of the variable by its probability and summing these products.

Question 27

For a typical normally distributed random variable, the standard deviation is equal to the variance.

Question 28

The collectively exhaustive set of events for flipping a coin is ________.

Question 29

________ probability is an estimate based on a personal belief, experience, and knowledge of a situation.

Question 30

Objective probabilities that can be stated prior to the occurrence of an event are ________.

Question 31

The cumulative probability for all six outcomes of tossing a fair die should end with the value ________.

Question 32

The standard normal distribution has a mean of one and a standard deviation of zero.

Question 33

The term for including all possible events that can occur in an experiment is ________.

Question 34

Another name for the mean of a probability distribution is its expected value.

Question 35

A ________ organizes numerical data to describe the events of an experiment.

Question 36

The events in an experiment are ________ if only one can occur at a time.

Question 37

The area under the normal curve represents probability.

Question 38

There is just as great a chance of a normally distributed random variable being over one standard deviation above the mean as there is being one standard deviation below the mean.

Question 39

An inspector correctly identifies defective products 90% of the time. For the next 10 products, the probability that he makes fewer than two incorrect inspections is 0.736.

Question 40

The variance of a discrete random variable is always greater than or equal to zero.

Question 41

If events A and B are independent, then P(A|B) = ________.

Question 42

The ________ normal distribution has a mean of 0 and a standard deviation of 1.

Question 43

In a binomial distribution process, there are ________ possible outcomes.

Question 44

A continuous random variable can take on a(n) ________ number of values within a given interval.

Question 45

Jim is considering pursuing an MS in Information Systems degree. He has applied to two different universities. The acceptance rate for applicants with similar qualifications is 20% for University X and 45% for University Y.
What is the probability that Jim will be accepted at both universities?

Question 46

A Venn diagram depicting two circles that do not overlap or touch in any way represents events that are ________.

Question 47

The ________ of a random variable is computed by multiplying each possible value of the variable by its probability and summing these products.

Question 48

Almost all of the data from a normal distribution fall within ________ standard deviations of the mean.

Question 49

A ________ is the probability of occurence of a single event.

Question 50

If events A and B are independent, then P(AB) = ________.

Question 51

________ is a measure of dispersion of random variable values about the expected value.

Question 52

The standard deviation of the standard normal distribution is equal to ________.

Question 53

One of the properties of the ________ distribution is that the probability of success remains constant over time.

Question 54

________ can enable one to improve marginal probabilities of the occurrence of an event by gathering additional information.

Question 55

The ________ test is a statistical test to see if an observed data fit a particular probability distribution.

Question 56

A succession of events that do not affect each other are ________.

Question 57

A ________ probability is the probability that an event will occur given that another event has already occurred.

Question 58

If two events A and B are not mutually exclusive, then P(A or
B) = ________.

Question 59

Altered marginal probability of an event based on additional information is a ________ probability.

Question 60

The expected value of the standard normal distribution is equal to ________.

Question 61

Assume X has the following probability distribution :
Compute the standard deviation of X.

Question 62

A fair die is rolled nine times. What is the probability that an odd number (1, 3, or 5) will occur less than 3 times?

Question 63

For a standard normal distribution, what is the probability that z is greater than 1.75?

Question 64

If x is normally distributed with a mean of 10 and a standard deviation of 3, then P(x ≤ 6) is equal to P( Z ≤ _____)?

Question 65

Two psychology majors, in two different sections of Clinical Psychology, were comparing test scores. The following gives the students' scores, class mean, and standard deviation for each section:

What is the z-score of the student from section 1 and what is the probability that a student in section 1 will score higher than 84?

Question 66

If X has the following probability distribution

Compute the expected value of X.

Question 67

A company markets educational software products, and is ready to place three new products on the market. Past experience has shown that for this particular software, the chance of "success" is 80%. Assume that the probability of success is independent for each product.
Find the probability that none of the 3 products is successful.

Question 68

A company markets educational software products, and is ready to place three new products on the market. Past experience has shown that for this particular software, the chance of "success" is 80%. Assume that the probability of success is independent for each product.
Find the probability that exactly 1 of the 3 products is successful.

Question 69

Employees of a local company are classified according to gender and job type. The following table summarizes the number of people in each job category.

If an employee is selected at random, what is the probability that the employee is male?

Question 70

Employees of a local company are classified according to gender and job type. The following table summarizes the number of people in each job category.

If an employee is selected at random, what is the probability that the employee is female given that the employee is a salaried staff member?

Question 71

Employees of a local company are classified according to gender and job type. The following table summarizes the number of people in each job category.

If an employee is selected at random, what is the probability that the employee is male and salaried staff?

Question 72

Which student scored better compared to the rest of their section?

Question 73

The weight of a loaf of bread is normally distributed with a mean of 22 oz and a standard deviation of 0.5 oz. What is the probability that a loaf is larger than 21 oz?

Question 74

A fair die is rolled 8 times. What is the probability that an even number (2, 4, or 6) will occur between 2 and 4 times?

Question 75

The Dean's Office keeps tracks of student complaints received each week. The probability distribution for complaints can be represented as a table as shown below. The random variable xi represents the number of complaints, and p(xi) is the probability of receiving xi complaints.

What is the average number of complaints received per week?

Question 76

Jim is considering pursuing an MS in Information Systems degree. He has applied to two different universities. The acceptance rate for applicants with similar qualifications is 20% for University X and 45% for University Y.
What is the probability that Jim will be accepted by at least one of the two universities?

Question 77

Employees of a local company are classified according to gender and job type. The following table summarizes the number of people in each job category.

If an employee is selected at random, what is the probability that the employee is female or works as a member of the administration

Question 78

Jim is considering pursuing an MS in Information Systems degree. He has applied to two different universities. The acceptance rate for applicants with similar qualifications is 20% for University X and 45% for University Y.
What is the probability that Jim will not be accepted at either university?

Question 79

Two psychology majors, in two different sections of Clinical Psychology, were comparing test scores. The following gives the students' scores, class mean, and standard deviation for each section:

What is the z-score of the student from section 2 and what is the probability that a student in section 2 will score higher than 75?

Question 80

The Dean's Office keeps tracks of student complaints received each week. The probability distribution for complaints can be represented as a table as shown below. The random variable xi represents the number of complaints, and p(xi) is the probability of receiving xi complaints.

What is the probability that they receive less than 3 complaints in a week?