Question 1

A normal distribution is symmetric;therefore the probability of being below the mean is 0.50 and the probability of being above the mean is 0.50.

Accepted Answer

A) True 
 B)False

Question 2

Repair Time
The time it takes a technician to fix a telephone problem is exponentially distributed with a mean of 15 minutes.
-{Repair Time Narrative} What is the probability that it will take a technician less than 10 minutes to fix a telephone problem?

Accepted Answer

The answer of Repair Time
The time it takes a technician...

Question 3

What happens to the shape,mean,and variance of a Student t distribution as the degrees of freedom increase?

Accepted Answer

As the degrees of freedom of t

Question 4

We define $F _ { A , v _ { 1 } , v _ { 2 } }$ as the value of the F with v1 and v2 degrees of freedom such that the area to its right under the F curve is A,while   is defined as the value such that the area to its left is A.

Accepted Answer

A) True 
 B)False

Question 5

A national standardized testing company can tell you your relative standing on an exam without divulging the mean or the standard deviation of the exam scores.

Accepted Answer

A) True 
 B)False

Question 6

The 10th percentile of a Z distribution has 10% of the Z-values lying above it.

Accepted Answer

A) True 
 B)False

Question 7

Which of the following can have an exponential distribution?

Accepted Answer

A)  Time between phone calls coming in to a technical support desk. 
B)  Time until the first customer arrives at the bank in the morning. 
C)  Lifetime of a new battery. 
D)  All of these choices are true. 
A)  Time between phone calls coming in to a technical support desk. 
B)  Time until the first customer arrives at the bank in the morning. 
C)  Lifetime of a new battery. 
D)  All of these choices are true.

Question 8

Light Bulb Lifetime
The lifetime of a light bulb (in hours)is exponentially distributed with$\lambda$ = 0.008.
-{Light Bulb Lifetime Narrative} What is the mean and standard deviation of the light bulb's lifetime?

Accepted Answer

@#LAT-DLM& = @#LAT-DLM& = 1/@#LAT-DLM& =

Question 9

As the ____________________ degrees of freedom increase,the mean of the F distribution approaches 1.

Accepted Answer

The answer of As the ____________________ degrees of freedom increase,the...

Question 10

The mean of the standard normal distribution is ____________________ and the standard deviation is ____________________.

Accepted Answer

The answer of The mean of the standard normal distribution...

Question 11

The exponential density function f(x):

Accepted Answer

A)  is bell-shaped. 
B)  is symmetrical. 
C)  approaches infinity as x approaches zero. 
D)  approaches zero as x approaches infinity. 
A)  is bell-shaped. 
B)  is symmetrical. 
C)  approaches infinity as x approaches zero. 
D)  approaches zero as x approaches infinity.

Question 12

A(n)____________________ random variable is one that assumes an uncountable number of possible values.

Accepted Answer

The answer of A(n)____________________ random variable is one that assumes...

Question 13

To be a legitimate probability density function,all possible values of f(x)must be non-negative.

Accepted Answer

A) True 
 B)False

Question 14

The Student t distribution with parameter v = 4 has a variance V(t)equal to:

Accepted Answer

A)  4 
B)  0 
C)  2 
D)  1 
A)  4 
B)  0 
C)  2 
D)  1

Question 15

Checking Accounts
A bank has determined that the monthly balances of the checking accounts of its customers are normally distributed with an average balance of $1,200 and a standard deviation of $250.
-{Checking Accounts Narrative} What proportion of customers have monthly balances more than $1,125?

Accepted Answer

The answer of Checking Accounts
A bank has determined that the...

Question 16

Electronics Test
The time it takes a student to finish a electronics test has a uniform distribution between 50 and 70 minutes.
-{Electronics Test Narrative} What is the probability density function for this uniform distribution?

Accepted Answer

The answer of Electronics Test
The time it takes a student...

Question 17

If X has a normal distribution with mean 60 and standard deviation 6,which value of X corresponds with the value z = 1.96?

Accepted Answer

A)  x = 71.76 
B)  x = 67.96 
C)  x = 61.96 
D)  x = 48.24 
A)  x = 71.76 
B)  x = 67.96 
C)  x = 61.96 
D)  x = 48.24

Question 18

The probability density function f(x)for a uniform random variable X defined over the interval [2,10] is

Accepted Answer

A)  0.20 
B)  8 
C)  4 
D)  None of these choices. 
A)  0.20 
B)  8 
C)  4 
D)  None of these choices.

Question 19

Waiting Time
The length of time patients must wait to see a doctor at an emergency room in a large hospital has a uniform distribution between 40 minutes and 3 hours.
-{Waiting Time Narrative} What is the probability that a patient would have to wait no more than one hour?

Accepted Answer

The answer of Waiting Time
The length of time patients must...

Question 20

Phone Orders
The L.L.Bean catalog department that receives the majority of its orders by telephone conducted a study to determine how long customers were willing to wait on hold before ordering a product.The length of time was found to be a random variable best approximated by an exponential distribution with a mean equal to 3 minutes.
-{Phone Orders Narrative} What proportion of customers having to hold more than 1.5 minutes will hang up before placing an order?

Accepted Answer

P(X > 1.5)

Exam 8: Continuous Probability Distributions

A normal distribution is symmetric;therefore the probability of being below the mean is 0.50 and the probability of being above the mean is 0.50.

Repair Time The time it takes a technician to fix a telephone problem is exponentially distributed with a mean of 15 minutes. -{Repair Time Narrative} What is the probability that it will take a technician less than 10 minutes to fix a telephone problem?

What happens to the shape,mean,and variance of a Student t distribution as the degrees of freedom increase?

We define FA,v1,v2F _ { A , v _ { 1 } , v _ { 2 } }FA,v1​,v2​​ as the value of the F with v1 and v2 degrees of freedom such that the area to its right under the F curve is A,while is defined as the value such that the area to its left is A.

A national standardized testing company can tell you your relative standing on an exam without divulging the mean or the standard deviation of the exam scores.

The 10th percentile of a Z distribution has 10% of the Z-values lying above it.

Which of the following can have an exponential distribution?

Light Bulb Lifetime The lifetime of a light bulb (in hours)is exponentially distributed with λ\lambdaλ = 0.008. -{Light Bulb Lifetime Narrative} What is the mean and standard deviation of the light bulb's lifetime?

As the ____________________ degrees of freedom increase,the mean of the F distribution approaches 1.

The mean of the standard normal distribution is ____________________ and the standard deviation is ____________________.

The exponential density function f(x):

A(n)____________________ random variable is one that assumes an uncountable number of possible values.

To be a legitimate probability density function,all possible values of f(x)must be non-negative.

The Student t distribution with parameter v = 4 has a variance V(t)equal to:

Electronics Test The time it takes a student to finish a electronics test has a uniform distribution between 50 and 70 minutes. -{Electronics Test Narrative} What is the probability density function for this uniform distribution?

If X has a normal distribution with mean 60 and standard deviation 6,which value of X corresponds with the value z = 1.96?

The probability density function f(x)for a uniform random variable X defined over the interval [2,10] is

Waiting Time The length of time patients must wait to see a doctor at an emergency room in a large hospital has a uniform distribution between 40 minutes and 3 hours. -{Waiting Time Narrative} What is the probability that a patient would have to wait no more than one hour?

What Is Statistics

Graphical Descriptive Techniques I

Graphical Descriptive Techniques II

A: Numerical Descriptive Techniques

B: Numerical Descriptive Techniques

C: Numerical Descriptive Techniques

Data Collection and Sampling

Probability

A: Random Variables and Discrete Probability Distributions

B: Random Variables and Discrete Probability Distributions

Sampling Distributions

Introduction to Estimation

Introduction to Hypothesis Testing

Inference About a Population

Inference About Comparing Two Populations

Analysis of Variance

Chi-Squared Tests

A: Simple Linear Regression and Correlation

B: Simple Linear Regression and Correlation

Multiple Regression

Model Building

Nonparametric Statistics

Time-Series Analysis and Forecasting

Statistical Process Control

Decision Analysis

Conclusion

Filters

Light Bulb Lifetime The lifetime of a light bulb (in hours)is exponentially distributed with $\lambda$ = 0.008. -{Light Bulb Lifetime Narrative} What is the mean and standard deviation of the light bulb's lifetime?

The mean of the standard normal distribution is and the standard deviation is .