Question 1

The area under an exponential curve can exceed 1 because the distribution is right-skewed.

Accepted Answer

A) True 
 B)False

Question 2

For Gardyloo Manufacturing,the true proportion of accounts receivable with some kind of error is 0.20.If an auditor randomly samples 225 accounts receivable,what is the approximate normal probability that 39 or fewer will contain errors?

Accepted Answer

A) 0.1797 
B) 0.2097 
C) 0.1587 
D) 0.0544 
A) 0.1797 
B) 0.2097 
C) 0.1587 
D) 0.0544

Question 3

The area under the normal curve between the 20th and 70th percentiles is equal to

Accepted Answer

A) 0.7000 
B) 0.5000 
C) 0.9193 
A) 0.7000 
B) 0.5000 
C) 0.9193

Question 4

In Melanie's Styling Salon,the time to complete a simple haircut is normally distributed with a mean of 25 minutes and a standard deviation of 4 minutes.What percentage of customers require less than 32 minutes for a simple haircut?

Accepted Answer

A) 95.99 percent 
B) 99.45 percent 
C) 97.72 percent 
D) 45.99 percent 
A) 95.99 percent 
B) 99.45 percent 
C) 97.72 percent 
D) 45.99 percent

Question 5

A software developer makes 175 phone calls to its current customers.There is an 8 percent chance of reaching a given customer (instead of a busy signal,no answer,or answering machine).The normal approximation of the probability of reaching at least 20 customers is

Accepted Answer

A) 0.022 
B) 0.007 
C) 0.063 
D) 0.937 
A) 0.022 
B) 0.007 
C) 0.063 
D) 0.937

Question 6

The figure shows a normal N(400,23)distribution.Find the x value for the shaded area.

Accepted Answer

A) 412.9 
B) 426.7 
C) 436.2 
D) 440.3 
A) 412.9 
B) 426.7 
C) 436.2 
D) 440.3

Question 7

The Excel function = 40*RAND()would generate random numbers with standard deviation approximately equal to

Accepted Answer

A) 13.33 
B) 20.00 
C) 11.55 
D) 19.27 
A) 13.33 
B) 20.00 
C) 11.55 
D) 19.27

Question 8

If arrivals occur at a mean rate of 3.6 events per hour,the exponential probability of waiting less than 0.5 hour for the next arrival is

Accepted Answer

A) 0.7122 
B) 0.8105 
C) 0.8347 
D) 0.7809 
A) 0.7122 
B) 0.8105 
C) 0.8347 
D) 0.7809

Question 9

The standard deviation of a normal random variable X is $20.Given that P(X ≤ $10)= 0.1841 we can determine that the mean of the distribution is equal to

Accepted Answer

A) $13 
B) $26 
C) $20 
D) $28 
A) $13 
B) $26 
C) $20 
D) $28

Question 10

A large number of applicants for admission to graduate study in business are given an aptitude test.Scores are normally distributed with a mean of 460 and standard deviation of 80.The top 2.5 percent of the applicants would have a score of at least (choose the nearest integer)

Accepted Answer

A) 606 
B) 617 
C) 600 
D) 646 
A) 606 
B) 617 
C) 600 
D) 646

Question 11

Which probability model is most appropriate to describe the waiting time (working days)until an office photocopier breaks down (i.e. ,requires unscheduled maintenance)?

Accepted Answer

A) Normal 
B) Uniform 
C) Exponential 
D) Poisson 
A) Normal 
B) Uniform 
C) Exponential 
D) Poisson

Question 12

Could this function be a PDF?

Accepted Answer

A) Yes 
B) No 
C) It depends on x. 
A) Yes 
B) No 
C) It depends on x.

Question 13

The figure shows a standard normal N(0,1)distribution.Find the z value for the shaded area.

Accepted Answer

A) −2.17 
B) −2.09 
C) −1.99 
D) −1.94 
A) −2.17 
B) −2.09 
C) −1.99 
D) −1.94

Question 14

The exponential distribution is always skewed right.

Accepted Answer

A) True 
 B)False

Question 15

The Excel function = 800*RAND()would generate random numbers with standard deviation approximately equal to

Accepted Answer

A) 200 
B) 188 
C) 231 
D) 400 
A) 200 
B) 188 
C) 231 
D) 400

Question 16

A random variable X is best described by a continuous uniform distribution from 20 to 45 inclusive.The standard deviation of this distribution is approximately

Accepted Answer

A) 52.1 
B) 32.5 
C) 6.85 
D) 7.22 
A) 52.1 
B) 32.5 
C) 6.85 
D) 7.22

Question 17

In a continuous distribution the

Accepted Answer

A) PDF is usually higher than the CDF. 
B) CDF is used to find left-tail probabilities. 
C) PDF shows the area under the curve. 
D) CDF is usually the same as the PDF. 
A) PDF is usually higher than the CDF. 
B) CDF is used to find left-tail probabilities. 
C) PDF shows the area under the curve. 
D) CDF is usually the same as the PDF.

Question 18

A company employs 300 employees.Each year,there is a 30 percent turnover rate for employees.We want to do a normal approximation to the binomial distribution of the number of employees who leave each year.For this normal approximation,the mean is ________ and the standard deviation is ________.

Accepted Answer

A) 90,63 
B) 90,7.937 
C) 90,30 
D) 90,15 
A) 90,63 
B) 90,7.937 
C) 90,30 
D) 90,15

Question 19

The variable in a normal distribution can assume any value between

Accepted Answer

A) −3 and +3 
B) −4 and +4 
C) −1 and +1 
D) −∞ and +∞ 
A) −3 and +3 
B) −4 and +4 
C) −1 and +1 
D) −∞ and +∞

Question 20

Could this function be a PDF?

Accepted Answer

A) Yes 
B) No 
C) It depends on x. 
A) Yes 
B) No 
C) It depends on x.

The area under an exponential curve can exceed 1 because the distribution is right-skewed.

For Gardyloo Manufacturing,the true proportion of accounts receivable with some kind of error is 0.20.If an auditor randomly samples 225 accounts receivable,what is the approximate normal probability that 39 or fewer will contain errors?

The area under the normal curve between the 20th and 70th percentiles is equal to

In Melanie's Styling Salon,the time to complete a simple haircut is normally distributed with a mean of 25 minutes and a standard deviation of 4 minutes.What percentage of customers require less than 32 minutes for a simple haircut?

A software developer makes 175 phone calls to its current customers.There is an 8 percent chance of reaching a given customer (instead of a busy signal,no answer,or answering machine).The normal approximation of the probability of reaching at least 20 customers is

The figure shows a normal N(400,23)distribution.Find the x value for the shaded area.

The Excel function = 40*RAND()would generate random numbers with standard deviation approximately equal to

If arrivals occur at a mean rate of 3.6 events per hour,the exponential probability of waiting less than 0.5 hour for the next arrival is

The standard deviation of a normal random variable X is $20.Given that P(X ≤ $10)= 0.1841 we can determine that the mean of the distribution is equal to

A large number of applicants for admission to graduate study in business are given an aptitude test.Scores are normally distributed with a mean of 460 and standard deviation of 80.The top 2.5 percent of the applicants would have a score of at least (choose the nearest integer)

Which probability model is most appropriate to describe the waiting time (working days)until an office photocopier breaks down (i.e. ,requires unscheduled maintenance)?

Could this function be a PDF?

The figure shows a standard normal N(0,1)distribution.Find the z value for the shaded area.

The exponential distribution is always skewed right.

The Excel function = 800*RAND()would generate random numbers with standard deviation approximately equal to

A random variable X is best described by a continuous uniform distribution from 20 to 45 inclusive.The standard deviation of this distribution is approximately

In a continuous distribution the

A company employs 300 employees.Each year,there is a 30 percent turnover rate for employees.We want to do a normal approximation to the binomial distribution of the number of employees who leave each year.For this normal approximation,the mean is and the standard deviation is .

The variable in a normal distribution can assume any value between

Could this function be a PDF?

Overview of Statistics

Data Collection

Describing Data Visually

Descriptive Statistics

Probability

Discrete Probability Distributions

Sampling Distributions and Estimation

One-Sample Hypothesis Tests

Two-Sample Hypothesis Tests

Analysis of Variance

Simple Regression

Multiple Regression

Chi-Square Tests

Filters

Exam 7: Continuous Probability Distributions

The area under an exponential curve can exceed 1 because the distribution is right-skewed.

For Gardyloo Manufacturing,the true proportion of accounts receivable with some kind of error is 0.20.If an auditor randomly samples 225 accounts receivable,what is the approximate normal probability that 39 or fewer will contain errors?

The area under the normal curve between the 20th and 70th percentiles is equal to

In Melanie's Styling Salon,the time to complete a simple haircut is normally distributed with a mean of 25 minutes and a standard deviation of 4 minutes.What percentage of customers require less than 32 minutes for a simple haircut?

A software developer makes 175 phone calls to its current customers.There is an 8 percent chance of reaching a given customer (instead of a busy signal,no answer,or answering machine).The normal approximation of the probability of reaching at least 20 customers is

The figure shows a normal N(400,23)distribution.Find the x value for the shaded area.

The Excel function = 40*RAND()would generate random numbers with standard deviation approximately equal to

If arrivals occur at a mean rate of 3.6 events per hour,the exponential probability of waiting less than 0.5 hour for the next arrival is

The standard deviation of a normal random variable X is $20.Given that P(X ≤ $10)= 0.1841 we can determine that the mean of the distribution is equal to

A large number of applicants for admission to graduate study in business are given an aptitude test.Scores are normally distributed with a mean of 460 and standard deviation of 80.The top 2.5 percent of the applicants would have a score of at least (choose the nearest integer)

Which probability model is most appropriate to describe the waiting time (working days)until an office photocopier breaks down (i.e. ,requires unscheduled maintenance)?

Could this function be a PDF?

The figure shows a standard normal N(0,1)distribution.Find the z value for the shaded area.

The exponential distribution is always skewed right.

The Excel function = 800*RAND()would generate random numbers with standard deviation approximately equal to

A random variable X is best described by a continuous uniform distribution from 20 to 45 inclusive.The standard deviation of this distribution is approximately

In a continuous distribution the

A company employs 300 employees.Each year,there is a 30 percent turnover rate for employees.We want to do a normal approximation to the binomial distribution of the number of employees who leave each year.For this normal approximation,the mean is ________ and the standard deviation is ________.

The variable in a normal distribution can assume any value between

Could this function be a PDF?

Overview of Statistics

Data Collection

Describing Data Visually

Descriptive Statistics

Probability

Discrete Probability Distributions

Sampling Distributions and Estimation

One-Sample Hypothesis Tests

Two-Sample Hypothesis Tests

Analysis of Variance

Simple Regression

Multiple Regression

Chi-Square Tests

Filters

A company employs 300 employees.Each year,there is a 30 percent turnover rate for employees.We want to do a normal approximation to the binomial distribution of the number of employees who leave each year.For this normal approximation,the mean is and the standard deviation is .