Question 1

Two events are independent if

Accepted Answer

A)  the two events occur at the same time.
B)  the probability of one or both events is greater than 1.
C)  P(A | 
B)   = P(
A)   or P(B | 
A)   = P(
B)  .
D)  None of these are correct. C

Question 2

The event containing the outcomes belonging to A or B or both is the __________ of A and B.

Accepted Answer

A)  union
B)  Venn diagram
C)  intersection
D)  complement A

Question 3

An experiment consists of determining the speed of automobiles on a highway by the use of radar equipment. The random variable in this experiment is a

Accepted Answer

A)  discrete random variable.
B)  continuous random variable.
C)  complex random variable.
D)  categorical random variable. B

Question 4

Which statement is true about mutually exclusive events?

Accepted Answer

A)  If events A and B cannot occur at the same time, they are called mutually exclusive.
B)  If either event A or event B must occur, they are called mutually exclusive.
C)  P(
A)   + P(
B)   = 1 for any events A and B that are mutually exclusive.
D)  None of these are correct.

Question 5

Sample space is

Accepted Answer

A)  a process that results in some outcome.
B)  the collection of all possible outcomes.
C)  the collection of events
D)  a subgroup of a population/the likelihood of an outcome.

Question 6

A joint probability is the

Accepted Answer

A)  sum of the probabilities of two events.
B)  probability of the intersection of two events.
C)  probability of the union of two events.
D)  sum of the probabilities of two independent events.

Question 7

The random variable X is known to be uniformly distributed between 2 and 12. Compute E(X), the expected value of the distribution.

Accepted Answer

A)  4
B)  5
C)  6
D)  7

Question 8

The number of minutes that Samantha waits to catch the bus is uniformly distributed between 0 and 15 minutes. What is the probability that Samantha has to wait less than 4.5 minutes to catch the bus?

Accepted Answer

A)  10%
B)  20%
C)  30%
D)  3%

Question 9

If a z-score is zero, then the corresponding x-value must be equal to the

Accepted Answer

A)  mean.
B)  median.
C)  mode.
D)  standard deviation.

Question 10

In the probability table below, which value is a marginal probability? ​
Completed
Obstacle Course Level
No
Yes
Total
Challenging
0)4
0)3
0)7
Easy
0)1
0)2
0)3
Total
0)5
0)5
1)0

Accepted Answer

A)  0.1
B)  1.0
C)  0.5
D)  0.4

Question 11

Probability is the

Accepted Answer

A)  number of successes divided by the number of failures.
B)  numerical measure of the likelihood that an event will occur.
C)  chance that an event will not happen.
D)  number of successes divided by the standard deviation of the distribution.

Question 12

Which of the following statements is correct?

Accepted Answer

A)  The binomial and normal distributions are both discrete probability distributions.
B)  The binomial and normal distributions are both continuous probability distributions.
C)  The binomial distribution is a continuous probability distribution, and the normal distribution is a discrete probability distribution.
D)  The binomial distribution is a discrete probability distribution and the normal distribution is a continuous probability distribution.

Question 13

A health conscious student faithfully wears a device that tracks his steps. Suppose that the distribution of the number of steps he takes in a day is normally distributed with a mean of 10,000 and a standard deviation of 1,500 steps. What percent of the days does he exceed 13,000 steps?

Accepted Answer

A)  2.28%
B)  5%
C)  95%
D)  97.72%

Question 14

All of the following are examples of discrete random variables except

Accepted Answer

A)  number of tickets sold.
B)  marital status.
C)  time.
D)  population of a city.

Question 15

In a normal distribution, which is greater, the mean or the median?

Accepted Answer

A)  Mean
B)  Median
C)  Neither the mean or the median (they are equal) 
D)  Cannot be determined with the information provided

Question 16

What is the total area under the normal distribution curve?

Accepted Answer

A)  It depends upon the mean and standard deviation
B)  It must be calculated
C)  1
D)  100

Question 17

The newest model of smart car is supposed to get excellent gas mileage. A thorough study showed that gas mileage (measured in miles per gallon) is normally distributed with a mean of 75 miles per gallon and a standard deviation of 10 miles per gallon. What value represents the 50th percentile of this distribution?

Accepted Answer

A)  75
B)  85
C)  95
D)  105

Question 18

A __________ describes the range and relative likelihood of all possible values for a random variable.

Accepted Answer

A)  probability distribution for a random variable
B)  probability mass function of an event
C)  density function
D)  probability

Question 19

The triangular distribution is a good model for __________ distributions.

Accepted Answer

A)  uniform
B)  skewed
C)  normal

Question 20

The random variable X is known to be uniformly distributed between 2 and 12. Compute the standard deviation of X.

Accepted Answer

A)  2.887
B)  3.464
C)  8.333
D)  12

Exam 5: Probability: an Introduction to Modeling Uncertainty

Two events are independent if

The event containing the outcomes belonging to A or B or both is the __________ of A and B.

An experiment consists of determining the speed of automobiles on a highway by the use of radar equipment. The random variable in this experiment is a

Which statement is true about mutually exclusive events?

Sample space is

A joint probability is the

The random variable X is known to be uniformly distributed between 2 and 12. Compute E(X) , the expected value of the distribution.

The number of minutes that Samantha waits to catch the bus is uniformly distributed between 0 and 15 minutes. What is the probability that Samantha has to wait less than 4.5 minutes to catch the bus?

If a z-score is zero, then the corresponding x-value must be equal to the

In the probability table below, which value is a marginal probability? Completed Obstacle Course Level No Yes Total Challenging 0) 4 0) 3 0) 7 Easy 0) 1 0) 2 0) 3 Total 0) 5 0) 5 1) 0

Probability is the

Which of the following statements is correct?

A health conscious student faithfully wears a device that tracks his steps. Suppose that the distribution of the number of steps he takes in a day is normally distributed with a mean of 10,000 and a standard deviation of 1,500 steps. What percent of the days does he exceed 13,000 steps?

All of the following are examples of discrete random variables except

In a normal distribution, which is greater, the mean or the median?

What is the total area under the normal distribution curve?

A __________ describes the range and relative likelihood of all possible values for a random variable.

The triangular distribution is a good model for __________ distributions.

The random variable X is known to be uniformly distributed between 2 and 12. Compute the standard deviation of X.

Exam 5: Probability: an Introduction to Modeling Uncertainty

Two events are independent if

The event containing the outcomes belonging to A or B or both is the __________ of A and B.

An experiment consists of determining the speed of automobiles on a highway by the use of radar equipment. The random variable in this experiment is a

Which statement is true about mutually exclusive events?

Sample space is

A joint probability is the

The random variable X is known to be uniformly distributed between 2 and 12. Compute E(X) , the expected value of the distribution.

The number of minutes that Samantha waits to catch the bus is uniformly distributed between 0 and 15 minutes. What is the probability that Samantha has to wait less than 4.5 minutes to catch the bus?

If a z-score is zero, then the corresponding x-value must be equal to the

In the probability table below, which value is a marginal probability? ​ Completed Obstacle Course Level No Yes Total Challenging 0) 4 0) 3 0) 7 Easy 0) 1 0) 2 0) 3 Total 0) 5 0) 5 1) 0

Probability is the

Which of the following statements is correct?

A health conscious student faithfully wears a device that tracks his steps. Suppose that the distribution of the number of steps he takes in a day is normally distributed with a mean of 10,000 and a standard deviation of 1,500 steps. What percent of the days does he exceed 13,000 steps?

All of the following are examples of discrete random variables except

In a normal distribution, which is greater, the mean or the median?

What is the total area under the normal distribution curve?

A __________ describes the range and relative likelihood of all possible values for a random variable.

The triangular distribution is a good model for __________ distributions.

The random variable X is known to be uniformly distributed between 2 and 12. Compute the standard deviation of X.

In the probability table below, which value is a marginal probability? Completed Obstacle Course Level No Yes Total Challenging 0) 4 0) 3 0) 7 Easy 0) 1 0) 2 0) 3 Total 0) 5 0) 5 1) 0