Question 1

What is the area under the normal curve between z = 0.0 and z = 1.79?

Accepted Answer

A) 0.4633 
B) 0.0367 
C) 0.9599 
D) 0.0401 
A) 0.4633 
B) 0.0367 
C) 0.9599 
D) 0.0401

Question 2

What is the area under the normal curve between z = −1.0 and z = −2.0?

Accepted Answer

A) 0.0228 
B) 0.3413 
C) 0.1359 
D) 0.4772 
A) 0.0228 
B) 0.3413 
C) 0.1359 
D) 0.4772

Question 3

Consider a standard normal random variable z. What is the value of z if the area to the right of z is 0.2643?

Accepted Answer

A) 0.72 
B) 0.28 
C) 1.46 
D) 0.63 
A) 0.72 
B) 0.28 
C) 1.46 
D) 0.63

Question 4

If an average of 12 12 customers are served per hour,what is the probability that the next customer will arrive in 6 minutes or less?

Accepted Answer

A) 0.61 
B) 0.30 
C) 0.70 
D) 0.39 
A) 0.61 
B) 0.30 
C) 0.70 
D) 0.39

Question 5

The time to fly between New York City and Chicago is uniformly distributed with a minimum of 120 minutes and a maximum of 150 minutes. What is the distribution's mean?

Accepted Answer

A) 120 minutes 
B) 150 minutes 
C) 135 minutes 
D) 270 minutes 
A) 120 minutes 
B) 150 minutes 
C) 135 minutes 
D) 270 minutes

Question 6

Some normal probability distributions are positively skewed.

Accepted Answer

A) True 
 B)False

Question 7

Ball-Bearings,Inc. produces ball bearings automatically on a Kronar BBX machine. For one of the ball bearings,the mean diameter is set at 20.00 mm (millimeters). The standard deviation of the production over a long period of time was computed to be 0.150 mm. What percent of the ball bearings will have diameters of 20.27 mm or more?

Accepted Answer

A) 41.00% 
B) 12.62% 
C) 3.59% 
D) 85.00% 
A) 41.00% 
B) 12.62% 
C) 3.59% 
D) 85.00%

Question 8

For a uniformly distributed random variable,x,P(x)= 1/(b − a).

Accepted Answer

A) True 
 B)False

Question 9

The mean score of a college entrance test is 500; the standard deviation is 75. The scores are normally distributed. What percent of the students scored below 320?

Accepted Answer

A) About 50.82% 
B) About 34.13% 
C) About 7.86% 
D) About 0.82% 
A) About 50.82% 
B) About 34.13% 
C) About 7.86% 
D) About 0.82%

Question 10

A group of normal distributions can have equal arithmetic means but different standard deviations.

Accepted Answer

A) True 
 B)False

Question 11

The average starting salary of individuals with a master's degree in statistics is normally distributed with a mean of $48,000 and a standard deviation of $6,000. What is the probability that a randomly selected individual with a master's in statistics will get a starting salary of at least $55,000?

Accepted Answer

A) 0.121 
B) 0.891 
C) 0.379 
D) 0.098 
A) 0.121 
B) 0.891 
C) 0.379 
D) 0.098

Question 12

The total area of a normal probability distribution is ________.

Accepted Answer

A) between −3.0 and 3.0 
B) 1.00 
C) dependent on a value of z 
D) approximated by the binomial distribution 
A) between −3.0 and 3.0 
B) 1.00 
C) dependent on a value of z 
D) approximated by the binomial distribution

Question 13

A binomial distribution has 100 trials (n = 100)with a probability of success of 0.25 (π = 0.25). We would like to find the probability of 34 or more successes using the normal distribution to approximate the binomial. Applying the continuity correction factor,what z-score should be used?

Accepted Answer

A) 2.079 
B) 2.194 
C) 1.963 
D) 0.25 
A) 2.079 
B) 2.194 
C) 1.963 
D) 0.25

Question 14

The shape of any uniform probability distribution is ________.

Accepted Answer

A) negatively skewed 
B) positively skewed 
C) rectangular 
D) bell-shaped 
A) negatively skewed 
B) positively skewed 
C) rectangular 
D) bell-shaped

Question 15

The normal distribution can be used to approximate a binomial distribution when nπ is less than 5.

Accepted Answer

A) True 
 B)False

Question 16

A new extended-life light bulb has an average life of 750 hours,with a standard deviation of 50 hours. If the life of these light bulbs approximates a normal distribution,about what percent of the distribution will be between 600 hours and 900 hours?

Accepted Answer

A) 95% 
B) 68% 
C) 34% 
D) 99.74% 
A) 95% 
B) 68% 
C) 34% 
D) 99.74%

Question 17

The standard normal distribution is a special normal distribution with a mean of 0 and a standard deviation of 1.

Accepted Answer

A) True 
 B)False

Question 18

The average score of 100 students taking a statistics final was 70 with a standard deviation of 7. Assuming a normal distribution,what test score separates the top 25% of the students from the lower 75% of students?

Accepted Answer

A) 70.00 
B) 74.69 
C) 65.31 
D) 75.25 
A) 70.00 
B) 74.69 
C) 65.31 
D) 75.25

Question 19

The average score of 100 students taking a statistics final was 70 with a standard deviation of 7. Assuming a normal distribution,what is the probability that a student scored greater than 65?

Accepted Answer

A) 0.2611 
B) 0.2389 
C) 0.7611 
D) −0.714 
A) 0.2611 
B) 0.2389 
C) 0.7611 
D) −0.714

Question 20

The number of different standard normal distributions is unlimited.

Accepted Answer

A) True 
 B)False

What is the area under the normal curve between z = 0.0 and z = 1.79?

What is the area under the normal curve between z = −1.0 and z = −2.0?

Consider a standard normal random variable z. What is the value of z if the area to the right of z is 0.2643?

If an average of 12 12 customers are served per hour,what is the probability that the next customer will arrive in 6 minutes or less?

The time to fly between New York City and Chicago is uniformly distributed with a minimum of 120 minutes and a maximum of 150 minutes. What is the distribution's mean?

Some normal probability distributions are positively skewed.

For a uniformly distributed random variable,x,P(x)= 1/(b − a).

The mean score of a college entrance test is 500; the standard deviation is 75. The scores are normally distributed. What percent of the students scored below 320?

A group of normal distributions can have equal arithmetic means but different standard deviations.

The average starting salary of individuals with a master's degree in statistics is normally distributed with a mean of $48,000 and a standard deviation of $6,000. What is the probability that a randomly selected individual with a master's in statistics will get a starting salary of at least $55,000?

The total area of a normal probability distribution is ________.

A binomial distribution has 100 trials (n = 100)with a probability of success of 0.25 (π = 0.25). We would like to find the probability of 34 or more successes using the normal distribution to approximate the binomial. Applying the continuity correction factor,what z-score should be used?

The shape of any uniform probability distribution is ________.

The normal distribution can be used to approximate a binomial distribution when nπ is less than 5.

A new extended-life light bulb has an average life of 750 hours,with a standard deviation of 50 hours. If the life of these light bulbs approximates a normal distribution,about what percent of the distribution will be between 600 hours and 900 hours?

The standard normal distribution is a special normal distribution with a mean of 0 and a standard deviation of 1.

The average score of 100 students taking a statistics final was 70 with a standard deviation of 7. Assuming a normal distribution,what test score separates the top 25% of the students from the lower 75% of students?

The average score of 100 students taking a statistics final was 70 with a standard deviation of 7. Assuming a normal distribution,what is the probability that a student scored greater than 65?

The number of different standard normal distributions is unlimited.

What Is Statistics

Describing Data: Frequency Tables, Frequency Distributions, and Graphic Presentation

Describing Data: Numerical Measures

Describing Data: Displaying and Exploring Data

A Survey of Probability Concepts

Discrete Probability Distributions

Sampling Methods and the Central Limit Theorem

Estimation and Confidence Intervals

One-Sample Tests of Hypothesis

Two-Sample Tests of Hypothesis

Analysis of Variance

Correlation and Linear Regression

Multiple Regression Analysis

Nonparametric Methods: Nominal Level Hypothesis Tests

Nonparametric Methods: Analysis of Ordinal Data

Index Numbers

Time Series and Forecasting

Statistical Process Control and Quality Management

An Introduction to Decision Theory

Filters

Exam 7: Continuous Probability Distributions

What is the area under the normal curve between z = 0.0 and z = 1.79?

What is the area under the normal curve between z = −1.0 and z = −2.0?

Consider a standard normal random variable z. What is the value of z if the area to the right of z is 0.2643?

If an average of 12 12 customers are served per hour,what is the probability that the next customer will arrive in 6 minutes or less?

The time to fly between New York City and Chicago is uniformly distributed with a minimum of 120 minutes and a maximum of 150 minutes. What is the distribution's mean?

Some normal probability distributions are positively skewed.

For a uniformly distributed random variable,x,P(x)= 1/(b − a).

The mean score of a college entrance test is 500; the standard deviation is 75. The scores are normally distributed. What percent of the students scored below 320?

A group of normal distributions can have equal arithmetic means but different standard deviations.

The total area of a normal probability distribution is ________.

A binomial distribution has 100 trials (n = 100)with a probability of success of 0.25 (π = 0.25). We would like to find the probability of 34 or more successes using the normal distribution to approximate the binomial. Applying the continuity correction factor,what z-score should be used?

The shape of any uniform probability distribution is ________.

The normal distribution can be used to approximate a binomial distribution when nπ is less than 5.

A new extended-life light bulb has an average life of 750 hours,with a standard deviation of 50 hours. If the life of these light bulbs approximates a normal distribution,about what percent of the distribution will be between 600 hours and 900 hours?

The standard normal distribution is a special normal distribution with a mean of 0 and a standard deviation of 1.

The average score of 100 students taking a statistics final was 70 with a standard deviation of 7. Assuming a normal distribution,what test score separates the top 25% of the students from the lower 75% of students?

The average score of 100 students taking a statistics final was 70 with a standard deviation of 7. Assuming a normal distribution,what is the probability that a student scored greater than 65?

The number of different standard normal distributions is unlimited.

What Is Statistics

Describing Data: Frequency Tables, Frequency Distributions, and Graphic Presentation

Describing Data: Numerical Measures

Describing Data: Displaying and Exploring Data

A Survey of Probability Concepts

Discrete Probability Distributions

Sampling Methods and the Central Limit Theorem

Estimation and Confidence Intervals

One-Sample Tests of Hypothesis

Two-Sample Tests of Hypothesis

Analysis of Variance

Correlation and Linear Regression

Multiple Regression Analysis

Nonparametric Methods: Nominal Level Hypothesis Tests

Nonparametric Methods: Analysis of Ordinal Data

Index Numbers

Time Series and Forecasting

Statistical Process Control and Quality Management

An Introduction to Decision Theory

Filters