Question 1

To convert a normally distributed variable X into a standard Z score we would:

Accepted Answer

A)  subtract the mean from the original observation and divide the result by the variance. 
B)  subtract the mean from the original observation and divide the result by the standard deviation. 
C)  add the mean and the original observation,then divide by the variance. 
D)  subtract the mean from the standard deviation and divide by the variance. 
A)  subtract the mean from the original observation and divide the result by the variance. 
B)  subtract the mean from the original observation and divide the result by the standard deviation. 
C)  add the mean and the original observation,then divide by the variance. 
D)  subtract the mean from the standard deviation and divide by the variance.

Question 2

A machine dispenses water into a glass.Assuming that the amount of water dispensed follows a continuous uniform distribution from 10 ounces to 16 ounces,the standard deviation of the amount of water dispensed is about:

Accepted Answer

A)  1.73 ounces. 
B)  3.00 ounces. 
C)  0.57 ounce. 
D)  3.51 ounces. 
A)  1.73 ounces. 
B)  3.00 ounces. 
C)  0.57 ounce. 
D)  3.51 ounces.

Question 3

If adult male heights are normally distributed with a mean of 180 cm and a standard deviation of 7 cm,how high should an aircraft lavatory door be to ensure that 99.9 percent of adult males will not have to stoop as they enter?

Accepted Answer

A)  195.7 cm 
B)  201.6 cm 
C)  207.3 cm 
D)  201.4 cm 
A)  195.7 cm 
B)  201.6 cm 
C)  207.3 cm 
D)  201.4 cm

Question 4

The triangular distribution T(10,20,50)has a standard deviation of:

Accepted Answer

A)  9.498. 
B)  9.225. 
C)  8.498. 
D)  7.710. 
A)  9.498. 
B)  9.225. 
C)  8.498. 
D)  7.710.

Question 5

A certain assembly line at Vexing Manufacturing Company averages 30 minutes between breakdowns.The median time between breakdowns is:

Accepted Answer

A)  30.0 minutes. 
B)  35.7 minutes. 
C)  25.4 minutes. 
D)  20.8 minutes. 
A)  30.0 minutes. 
B)  35.7 minutes. 
C)  25.4 minutes. 
D)  20.8 minutes.

Question 6

Exam scores were normal in BIO 200.Jason's exam score was one standard deviation above the mean.What percentile is he in?

Accepted Answer

A)  68th 
B)  75th 
C)  78th 
D)  84th 
A)  68th 
B)  75th 
C)  78th 
D)  84th

Question 7

TotCo is developing a new deluxe baby bassinet.If the length of a newborn baby is normally distributed with a mean of 50 cm and a standard deviation of 5 cm,what should be the interior length of the bassinet to ensure that 99 percent of newborn babies will fit,with a safety margin of 15 cm on each end of the bassinet?

Accepted Answer

A)  95.45 cm 
B)  85.22 cm 
C)  91.63 cm 
D)  98.92 cm 
A)  95.45 cm 
B)  85.22 cm 
C)  91.63 cm 
D)  98.92 cm

Question 8

The ages of job applicants for a security guard position are uniformly distributed between 25 and 65.Could a 25-year-old job applicant be two standard deviations below the mean (or more than two standard deviations)?

Accepted Answer

A)  Yes. 
B)  No. 
C)  Impossible to determine from given information. 
A)  Yes. 
B)  No. 
C)  Impossible to determine from given information.

Question 9

If arrivals follow a Poisson distribution with mean 1.2 arrivals per minute,find the 75th percentile of waiting times until the next arrival (i.e. ,75 percent below).

Accepted Answer

A)  1.155 minutes (69.3 seconds) 
B)  0.240 minute (14.4 seconds) 
C)  1.919 minutes (115.1 seconds) 
A)  1.155 minutes (69.3 seconds) 
B)  0.240 minute (14.4 seconds) 
C)  1.919 minutes (115.1 seconds)

Question 10

The exponential distribution describes the number of arrivals per unit of time.

Accepted Answer

A) True 
 B)False

Question 11

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 12

The triangular distribution T(0,10,20)is skewed left.

Accepted Answer

A) True 
 B)False

Question 13

Historically,the default rate on a certain type of commercial loan is 20 percent.If a bank makes 100 of these loans,what is the approximate probability that at least 26 will result in default?

Accepted Answer

A)  0.2000 
B)  0.0668 
C)  0.0846 
D)  0.0336 
A)  0.2000 
B)  0.0668 
C)  0.0846 
D)  0.0336

Question 14

For which binomial distribution would a normal approximation be most acceptable?

Accepted Answer

A)  n = 50,π = 0.05 
B)  n = 100,π = 0.04 
C)  n = 40,π = 0.25 
D)  n = 400,π = 0.02 
A)  n = 50,π = 0.05 
B)  n = 100,π = 0.04 
C)  n = 40,π = 0.25 
D)  n = 400,π = 0.02

Question 15

The exponential distribution can be either right-skewed or left-skewed,depending on λ.

Accepted Answer

A) True 
 B)False

Question 16

Compared to the area between z = 1.00 and z = 1.25,the area between z = 2.00 and z = 2.25 in the standard normal distribution will be:

Accepted Answer

A)  smaller. 
B)  larger. 
C)  the same. 
D)  impossible to compare without knowing μ and σ. 
A)  smaller. 
B)  larger. 
C)  the same. 
D)  impossible to compare without knowing μ and σ.

Question 17

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

Accepted Answer

A)  .2407. 
B)  .1653. 
C)  .1222. 
D)  .5000. 
A)  .2407. 
B)  .1653. 
C)  .1222. 
D)  .5000.

Question 18

The random variable X is normally distributed with mean of 80 and variance of 36.The 67th percentile of the distribution is:

Accepted Answer

A)  72.00. 
B)  95.84. 
C)  90.00. 
D)  82.64. 
A)  72.00. 
B)  95.84. 
C)  90.00. 
D)  82.64.

Question 19

Experience suggests that 4 percent of all college students have had a tonsillectomy.In a sample of 300 college students,we need to find the probability that at least 10 have had a tonsillectomy.It is acceptable to use the normal distribution to estimate this probability.

Accepted Answer

A) True 
 B)False

Question 20

Bob's z-score for the last exam was -1.15 in FIN 417,"Capital Budgeting Strategies." Bob said,"Yipe! My score is within the bottom quartile." Assuming a normal distribution,is Bob right?

Accepted Answer

A)  Yes 
B)  No 
C)  Must know the class size to answer 
A)  Yes 
B)  No 
C)  Must know the class size to answer

To convert a normally distributed variable X into a standard Z score we would:

A machine dispenses water into a glass.Assuming that the amount of water dispensed follows a continuous uniform distribution from 10 ounces to 16 ounces,the standard deviation of the amount of water dispensed is about:

If adult male heights are normally distributed with a mean of 180 cm and a standard deviation of 7 cm,how high should an aircraft lavatory door be to ensure that 99.9 percent of adult males will not have to stoop as they enter?

The triangular distribution T(10,20,50)has a standard deviation of:

A certain assembly line at Vexing Manufacturing Company averages 30 minutes between breakdowns.The median time between breakdowns is:

Exam scores were normal in BIO 200.Jason's exam score was one standard deviation above the mean.What percentile is he in?

The ages of job applicants for a security guard position are uniformly distributed between 25 and 65.Could a 25-year-old job applicant be two standard deviations below the mean (or more than two standard deviations)?

If arrivals follow a Poisson distribution with mean 1.2 arrivals per minute,find the 75^th percentile of waiting times until the next arrival (i.e. ,75 percent below).

The exponential distribution describes the number of arrivals per unit of time.

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 triangular distribution T(0,10,20)is skewed left.

Historically,the default rate on a certain type of commercial loan is 20 percent.If a bank makes 100 of these loans,what is the approximate probability that at least 26 will result in default?

For which binomial distribution would a normal approximation be most acceptable?

The exponential distribution can be either right-skewed or left-skewed,depending on λ.

Compared to the area between z = 1.00 and z = 1.25,the area between z = 2.00 and z = 2.25 in the standard normal distribution will be:

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

The random variable X is normally distributed with mean of 80 and variance of 36.The 67^th percentile of the distribution is:

Experience suggests that 4 percent of all college students have had a tonsillectomy.In a sample of 300 college students,we need to find the probability that at least 10 have had a tonsillectomy.It is acceptable to use the normal distribution to estimate this probability.

Bob's z-score for the last exam was -1.15 in FIN 417,"Capital Budgeting Strategies." Bob said,"Yipe! My score is within the bottom quartile." Assuming a normal distribution,is Bob right?

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

Time-Series Analysis

Chi-Square Tests

Nonparametric Tests

Quality Management

Filters

Exam 7: Continuous Probability Distributions

To convert a normally distributed variable X into a standard Z score we would:

A machine dispenses water into a glass.Assuming that the amount of water dispensed follows a continuous uniform distribution from 10 ounces to 16 ounces,the standard deviation of the amount of water dispensed is about:

If adult male heights are normally distributed with a mean of 180 cm and a standard deviation of 7 cm,how high should an aircraft lavatory door be to ensure that 99.9 percent of adult males will not have to stoop as they enter?

The triangular distribution T(10,20,50)has a standard deviation of:

A certain assembly line at Vexing Manufacturing Company averages 30 minutes between breakdowns.The median time between breakdowns is:

Exam scores were normal in BIO 200.Jason's exam score was one standard deviation above the mean.What percentile is he in?

The ages of job applicants for a security guard position are uniformly distributed between 25 and 65.Could a 25-year-old job applicant be two standard deviations below the mean (or more than two standard deviations)?

If arrivals follow a Poisson distribution with mean 1.2 arrivals per minute,find the 75th percentile of waiting times until the next arrival (i.e. ,75 percent below).

The exponential distribution describes the number of arrivals per unit of time.

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 triangular distribution T(0,10,20)is skewed left.

Historically,the default rate on a certain type of commercial loan is 20 percent.If a bank makes 100 of these loans,what is the approximate probability that at least 26 will result in default?

For which binomial distribution would a normal approximation be most acceptable?

The exponential distribution can be either right-skewed or left-skewed,depending on λ.

Compared to the area between z = 1.00 and z = 1.25,the area between z = 2.00 and z = 2.25 in the standard normal distribution will be:

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

The random variable X is normally distributed with mean of 80 and variance of 36.The 67th percentile of the distribution is:

Experience suggests that 4 percent of all college students have had a tonsillectomy.In a sample of 300 college students,we need to find the probability that at least 10 have had a tonsillectomy.It is acceptable to use the normal distribution to estimate this probability.

Bob's z-score for the last exam was -1.15 in FIN 417,"Capital Budgeting Strategies." Bob said,"Yipe! My score is within the bottom quartile." Assuming a normal distribution,is Bob right?

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

Time-Series Analysis

Chi-Square Tests

Nonparametric Tests

Quality Management

Filters

If arrivals follow a Poisson distribution with mean 1.2 arrivals per minute,find the 75^th percentile of waiting times until the next arrival (i.e. ,75 percent below).

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 random variable X is normally distributed with mean of 80 and variance of 36.The 67^th percentile of the distribution is: