Question 1

When a single die is rolled, each of the six sides are equally likely. This is an example of a uniform distribution.

Accepted Answer

A) True 
 B)False

Question 2

For a standardized normal distribution, calculate P(-1.28 < z < 1.75).

Accepted Answer

A)  0.3997 
B)  0.4599 
C)  0.1404 
D)  0.8596 
A)  0.3997 
B)  0.4599 
C)  0.1404 
D)  0.8596

Question 3

The transportation manager for the State of New Jersey has determined that the time between arrivals at a toll booth on the state's turnpike is exponentially distributed with λ = 4 cars per minute. Based on this, the average time between arrivals is:

Accepted Answer

A)  15 seconds. 
B)  12 seconds. 
C)  25 seconds. 
D)  4 minutes. 
A)  15 seconds. 
B)  12 seconds. 
C)  25 seconds. 
D)  4 minutes.

Question 4

An electronics repair shop has determined that the time between failures for a particular electronic component part is exponentially distributed with a mean time between failures of 200 hours. Based on this information, the probability that a part will fail between 20 and 100 hours is approximately 0.30.

Accepted Answer

A) True 
 B)False

Question 5

In a standard normal distribution, the probability P(-1.00< z < 1.20) is the same as:

Accepted Answer

A)  P(1< z < 1.20) - P(0 < z < 1.00). 
B)  P(1< z < 1.20) - 2*P(0 < z < 1.00). 
C)  2 ∗ P(1< z < 1.20) - P(0 < z <1.00). 
D)  P(1 < z < 1.20) + 2 ∗ P(0 < z <1.00). 
A)  P(1< z < 1.20) - P(0 < z < 1.00). 
B)  P(1< z < 1.20) - 2*P(0 < z < 1.00). 
C)  2 ∗ P(1< z < 1.20) - P(0 < z <1.00). 
D)  P(1 < z < 1.20) + 2 ∗ P(0 < z <1.00).

Question 6

A random variable is normally distributed with a mean of 25 and a standard deviation of 5. If an observation is randomly selected from the distribution, determine two values of which the smallest has 25% of the values below it and the largest has 25% of the values above it.

Accepted Answer

A)  18.85 and 27.94 
B)  19.31 and 21.12 
C)  16.23 and 18.82 
D)  21.65 and 28.35 
A)  18.85 and 27.94 
B)  19.31 and 21.12 
C)  16.23 and 18.82 
D)  21.65 and 28.35

Question 7

It is assumed that the time failures for an electronic component are exponentially distributed with a mean of 50 hours between consecutive failures. Based on this information, what is the probability that a randomly selected part will fail in less than 10 hours?

Accepted Answer

A)  About 0.82 
B)  About 0.20 
C)  About 0.33 
D)  About 0.18 
A)  About 0.82 
B)  About 0.20 
C)  About 0.33 
D)  About 0.18

Question 8

An assembly process takes between 20 and 40 minutes to complete with the distribution of time thought to be uniformly distributed. Based on this, the percentage of assemblies that require less than 25 minutes is 0.05.

Accepted Answer

A) True 
 B)False

Question 9

The State Department of Forests has determined that annual tree growth in a particular forest area is normally distributed with a mean equal to 17 inches and a standard deviation equal to 6 inches. Based on this information, it is possible for a randomly selected tree not to have grown any during a year.

Accepted Answer

A) True 
 B)False

Question 10

Students who have completed a speed reading course have reading speeds that are normally distributed with a mean of 950 words per minute and a standard deviation equal to 220 words per minute. Based on this information, what is the probability of a student reading at more than 1400 words per minute after finishing the course?

Accepted Answer

A)  0.0202 
B)  0.5207 
C)  0.4798 
D)  0.9798 
A)  0.0202 
B)  0.5207 
C)  0.4798 
D)  0.9798

Question 11

It is assumed that the time failures for an electronic component are exponentially distributed with a mean of 50 hours between consecutive failures. What is the probability that a component will be functioning after 60 hours?

Accepted Answer

A)  Approximately 0.30 
B)  About 0.70 
C)  About 0.21 
D)  About 0.49 
A)  Approximately 0.30 
B)  About 0.70 
C)  About 0.21 
D)  About 0.49

Question 12

A randomly selected customer support wait time (from a normal distribution) is calculated to be 1.8 standard deviations above its mean. What is the probability that another randomly selected customer wait time from the distribution will be less than 1.8 standard deviations from the mean?

Accepted Answer

A)  0.0359 
B)  0.9641 
C)  0.9281 
D)  0.9281 .. 
A)  0.0359 
B)  0.9641 
C)  0.9281 
D)  0.9281 ..

Question 13

The standard normal distribution has a mean of 0 and a standard deviation of 1.0.

Accepted Answer

A) True 
 B)False

Question 14

The fares received by taxi drivers working for the City Taxi line are normally distributed with a mean of $12.50 and a standard deviation of $3.25. Suppose a driver has four consecutive fares that are less than $6.00. What is the probability of this happening?

Accepted Answer

Since this is a normal distribution prob

Question 15

The fares received by taxi drivers working for the City Taxi line are normally distributed with a mean of $12.50 and a standard deviation of $3.25. Based on this information, what is the probability that a specific fare will exceed $15.00?

Accepted Answer

Since this is a normal distribution prob

Question 16

A major U.S. automaker has determined that the city mileage for one of its new SUV models is normally distributed with a mean equal to 15.2 mpg. A report issued by the company indicated that 22 percent of the SUV model vehicles will get more than 17 mpg in the city. Given this information, what is the city mileage standard deviation for this SUV model?

Accepted Answer

A)  0.77 mpg 
B)  Approximately 2.34 mpg 
C)  1.8 mpg 
D)  Approximately 3.1 mpg 
A)  0.77 mpg 
B)  Approximately 2.34 mpg 
C)  1.8 mpg 
D)  Approximately 3.1 mpg

Question 17

Consider a random variable, z, that has a standardized normal distribution. Determine P (1.28 < z < 2.33).

Accepted Answer

A)  0.0126 
B)  0.3997 
C)  0.0904 
D)  0.4901 
A)  0.0126 
B)  0.3997 
C)  0.0904 
D)  0.4901

Question 18

All symmetric distributions can be assumed normally distributed.

Accepted Answer

A) True 
 B)False

Question 19

For a standardized normal distribution, determine a value, say z0, so that P(z ≤ z0) = 0.01.

Accepted Answer

A)  -2.33 
B)  -1.96 
C)  2.33 
D)  1.96 
A)  -2.33 
B)  -1.96 
C)  2.33 
D)  1.96

Question 20

Consider a random variable, z, that has a standardized normal distribution. Determine P(0 < z < 1.96).

Accepted Answer

A)  0.1250 
B)  0.5250 
C)  0.3250 
D)  0.4750 
A)  0.1250 
B)  0.5250 
C)  0.3250 
D)  0.4750

When a single die is rolled, each of the six sides are equally likely. This is an example of a uniform distribution.

For a standardized normal distribution, calculate P(-1.28 < z < 1.75).

The transportation manager for the State of New Jersey has determined that the time between arrivals at a toll booth on the state's turnpike is exponentially distributed with λ = 4 cars per minute. Based on this, the average time between arrivals is:

In a standard normal distribution, the probability P(-1.00< z < 1.20) is the same as:

A random variable is normally distributed with a mean of 25 and a standard deviation of 5. If an observation is randomly selected from the distribution, determine two values of which the smallest has 25% of the values below it and the largest has 25% of the values above it.

It is assumed that the time failures for an electronic component are exponentially distributed with a mean of 50 hours between consecutive failures. Based on this information, what is the probability that a randomly selected part will fail in less than 10 hours?

An assembly process takes between 20 and 40 minutes to complete with the distribution of time thought to be uniformly distributed. Based on this, the percentage of assemblies that require less than 25 minutes is 0.05.

It is assumed that the time failures for an electronic component are exponentially distributed with a mean of 50 hours between consecutive failures. What is the probability that a component will be functioning after 60 hours?

A randomly selected customer support wait time (from a normal distribution) is calculated to be 1.8 standard deviations above its mean. What is the probability that another randomly selected customer wait time from the distribution will be less than 1.8 standard deviations from the mean?

The standard normal distribution has a mean of 0 and a standard deviation of 1.0.

The fares received by taxi drivers working for the City Taxi line are normally distributed with a mean of $12.50 and a standard deviation of $3.25. Suppose a driver has four consecutive fares that are less than $6.00. What is the probability of this happening?

The fares received by taxi drivers working for the City Taxi line are normally distributed with a mean of $12.50 and a standard deviation of $3.25. Based on this information, what is the probability that a specific fare will exceed $15.00?

Consider a random variable, z, that has a standardized normal distribution. Determine P (1.28 < z < 2.33).

All symmetric distributions can be assumed normally distributed.

For a standardized normal distribution, determine a value, say z0, so that P(z ≤ z0) = 0.01.

Consider a random variable, z, that has a standardized normal distribution. Determine P(0 < z < 1.96).

The Where, Why, and How of Data Collection

Graphs, Charts and Tablesdescribing Your Data

Describing Data Using Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Introduction to Sampling Distributions

Estimating Single Population Parameters

Introduction to Hypothesis Testing

Estimation and Hypothesis Testing for Two Population Parameters

Hypothesis Tests and Estimation for Population Variances

Analysis of Variance

Goodness-Of-Fit Tests and Contingency Analysis

Introduction to Linear Regression and Correlation Analysis

Multiple Regression Analysis and Model Building

Analyzing and Forecasting Time-Series Data

Introduction to Nonparametric Statistics

Introducing Business Analytics

Introduction to Decision Analysis

Introduction to Quality and Statistical Process Control

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Exam 6: Introduction to Continuous Probability Distributions

When a single die is rolled, each of the six sides are equally likely. This is an example of a uniform distribution.

For a standardized normal distribution, calculate P(-1.28 < z < 1.75).

The transportation manager for the State of New Jersey has determined that the time between arrivals at a toll booth on the state's turnpike is exponentially distributed with λ = 4 cars per minute. Based on this, the average time between arrivals is:

In a standard normal distribution, the probability P(-1.00< z < 1.20) is the same as:

A random variable is normally distributed with a mean of 25 and a standard deviation of 5. If an observation is randomly selected from the distribution, determine two values of which the smallest has 25% of the values below it and the largest has 25% of the values above it.

It is assumed that the time failures for an electronic component are exponentially distributed with a mean of 50 hours between consecutive failures. Based on this information, what is the probability that a randomly selected part will fail in less than 10 hours?

An assembly process takes between 20 and 40 minutes to complete with the distribution of time thought to be uniformly distributed. Based on this, the percentage of assemblies that require less than 25 minutes is 0.05.

It is assumed that the time failures for an electronic component are exponentially distributed with a mean of 50 hours between consecutive failures. What is the probability that a component will be functioning after 60 hours?

A randomly selected customer support wait time (from a normal distribution) is calculated to be 1.8 standard deviations above its mean. What is the probability that another randomly selected customer wait time from the distribution will be less than 1.8 standard deviations from the mean?

The standard normal distribution has a mean of 0 and a standard deviation of 1.0.

The fares received by taxi drivers working for the City Taxi line are normally distributed with a mean of $12.50 and a standard deviation of $3.25. Suppose a driver has four consecutive fares that are less than $6.00. What is the probability of this happening?

The fares received by taxi drivers working for the City Taxi line are normally distributed with a mean of $12.50 and a standard deviation of $3.25. Based on this information, what is the probability that a specific fare will exceed $15.00?

Consider a random variable, z, that has a standardized normal distribution. Determine P (1.28 < z < 2.33).

All symmetric distributions can be assumed normally distributed.

For a standardized normal distribution, determine a value, say z0, so that P(z ≤ z0) = 0.01.

Consider a random variable, z, that has a standardized normal distribution. Determine P(0 < z < 1.96).

The Where, Why, and How of Data Collection

Graphs, Charts and Tablesdescribing Your Data

Describing Data Using Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Introduction to Sampling Distributions

Estimating Single Population Parameters

Introduction to Hypothesis Testing

Estimation and Hypothesis Testing for Two Population Parameters

Hypothesis Tests and Estimation for Population Variances

Analysis of Variance

Goodness-Of-Fit Tests and Contingency Analysis

Introduction to Linear Regression and Correlation Analysis

Multiple Regression Analysis and Model Building

Analyzing and Forecasting Time-Series Data

Introduction to Nonparametric Statistics

Introducing Business Analytics

Introduction to Decision Analysis

Introduction to Quality and Statistical Process Control

Filters