Question 1

The value of an F distribution with v1 = 6 and v2 = 9 degrees of freedom such that the area to its right is 0.05 is 3.37.

Accepted Answer

A) True 
 B)False

Question 2

Lamont took a psychology exam whose mean was 70 with standard deviation 5.He also took a calculus exam whose mean was 80 with standard deviation 10.He scored 85 on both exams.On which exam did he do better compared to the other students who took the exam?

Accepted Answer

A)  He did better on the psychology exam,comparatively speaking. 
B)  He did better on the calculus exam,comparatively speaking. 
C)  He did the same on both exams,relatively speaking. 
D)  Cannot tell without more information. 
A)  He did better on the psychology exam,comparatively speaking. 
B)  He did better on the calculus exam,comparatively speaking. 
C)  He did the same on both exams,relatively speaking. 
D)  Cannot tell without more information.

Question 3

An exponential random variable is an example of a(n)____________________ random variable.

Accepted Answer

The answer of An exponential random variable is an example...

Question 4

Calculus Scores
Scores of high school students on a national calculus exam were normally distributed with a mean of 86 and a standard deviation of 4.(Total possible points = 100. )
-{Calculus Scores Narrative} What is the probability that a randomly selected student will have a score between 80 and 90?

Accepted Answer

The answer of Calculus Scores
Scores of high school students on...

Question 5

Which of the following distributions can take on negative values?

Accepted Answer

A)  Student t 
B)  $\chi$2 
C)  F 
D)  None of these choices. 
A)  Student t 
B)  $\chi$2 
C)  F 
D)  None of these choices.

Question 6

Which of the following statements is true?

Accepted Answer

A)  The chi-squared distribution is positively skewed. 
B)  All the values of the chi-squared distribution are non-negative. 
C)  The shape of the chi-squared distribution depends on its degrees of freedom. 
D)  All of these choices are true. 
A)  The chi-squared distribution is positively skewed. 
B)  All the values of the chi-squared distribution are non-negative. 
C)  The shape of the chi-squared distribution depends on its degrees of freedom. 
D)  All of these choices are true.

Question 7

Light Bulb Lifetime
The lifetime of a light bulb (in hours)is exponentially distributed with$\lambda$ = 0.008.
-{Light Bulb Lifetime Narrative} Find the probability that a light bulb will last between 120 and 140 hours.

Accepted Answer

P(120@#LAT-DLM& X @#LAT-DLM& 140)= e^-

Question 8

The shape of an F distribution is ____________________.

Accepted Answer

positively

Question 9

Most values of a standard normal distribution lie between:

Accepted Answer

A)  0 and 1 
B) -3 and 3 
C)  0 and 3 
D)  minus infinity and plus infinity 
A)  0 and 1 
B) -3 and 3 
C)  0 and 3 
D)  minus infinity and plus infinity

Question 10

A continuous random variable X has a uniform distribution between 5 and 15 (inclusive),then the probability that X falls between 10 and 20 is 1.0.

Accepted Answer

A) True 
 B)False

Question 11

What happens to the shape,mean,and variance of a c2 distribution as the degrees of freedom increase?

Accepted Answer

The shape becomes le

Question 12

IT Graduates Salary
The recent average starting salary for new college graduates in IT systems is $47,500.Assume salaries are normally distributed with a standard deviation of $4,500.
-{IT Graduates Salary Narrative} What is the cutoff for the bottom 5% of the salaries?

Accepted Answer

The answer of IT Graduates Salary
The recent average starting salary...

Question 13

As the degrees of freedom approach infinity,the values of a Student t distribution approach those of a standard normal distribution.

Accepted Answer

A) True 
 B)False

Question 14

Suppose X has a normal distribution with mean 40 and standard deviation 2.Shifting all the X values to the right 10 units results in a normal distribution with mean ____________________ and standard deviation ____________________.

Accepted Answer

The answer of Suppose X has a normal distribution with...

Question 15

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} Find the time at which 50% of the customers will continue to hold?

Accepted Answer

P(X > x)= e ^-

Question 16

Suppose f(x)= 1/4 over the range a$\le$ x $\le$ b,and suppose P(X > 4)= 1/2.What are the values for a and b?

Accepted Answer

A)  0 and 4 
B)  2 and 6 
C)  Can be any range of x values whose length (b - a)equals 4. 
D)  Cannot answer with the information given. 
A)  0 and 4 
B)  2 and 6 
C)  Can be any range of x values whose length (b - a)equals 4. 
D)  Cannot answer with the information given.

Question 17

Suppose X has a normal distribution with mean 70 and standard deviation 5.The 50th percentile of X is 70.

Accepted Answer

A) True 
 B)False

Question 18

The variance of a Student t random variable with v degrees of freedom (v > 2)is always greater than 1.

Accepted Answer

A) True 
 B)False

Question 19

Suppose X is a normal random variable with mean 70 and standard deviation 3.Then P(X = 3)= ____________________.

Accepted Answer

The answer of Suppose X is a normal random variable...

Question 20

Which of the following is not a characteristic for a normal distribution?

Accepted Answer

A)  It is symmetrical. 
B)  The mean is always zero. 
C)  The mean,median,and mode are all equal. 
D)  It is a bell-shaped distribution. 
A)  It is symmetrical. 
B)  The mean is always zero. 
C)  The mean,median,and mode are all equal. 
D)  It is a bell-shaped distribution.

Exam 8: Continuous Probability Distributions

The value of an F distribution with v1 = 6 and v2 = 9 degrees of freedom such that the area to its right is 0.05 is 3.37.

Lamont took a psychology exam whose mean was 70 with standard deviation 5.He also took a calculus exam whose mean was 80 with standard deviation 10.He scored 85 on both exams.On which exam did he do better compared to the other students who took the exam?

An exponential random variable is an example of a(n)____________________ random variable.

Which of the following distributions can take on negative values?

Which of the following statements is true?

Light Bulb Lifetime The lifetime of a light bulb (in hours)is exponentially distributed with λ\lambdaλ = 0.008. -{Light Bulb Lifetime Narrative} Find the probability that a light bulb will last between 120 and 140 hours.

The shape of an F distribution is ____________________.

Most values of a standard normal distribution lie between:

A continuous random variable X has a uniform distribution between 5 and 15 (inclusive),then the probability that X falls between 10 and 20 is 1.0.

What happens to the shape,mean,and variance of a c2 distribution as the degrees of freedom increase?

IT Graduates Salary The recent average starting salary for new college graduates in IT systems is $47,500.Assume salaries are normally distributed with a standard deviation of $4,500. -{IT Graduates Salary Narrative} What is the cutoff for the bottom 5% of the salaries?

As the degrees of freedom approach infinity,the values of a Student t distribution approach those of a standard normal distribution.

Suppose X has a normal distribution with mean 40 and standard deviation 2.Shifting all the X values to the right 10 units results in a normal distribution with mean ____________________ and standard deviation ____________________.

Suppose f(x)= 1/4 over the range a ≤\le≤ x ≤\le≤ b,and suppose P(X > 4)= 1/2.What are the values for a and b?

Suppose X has a normal distribution with mean 70 and standard deviation 5.The 50th percentile of X is 70.

The variance of a Student t random variable with v degrees of freedom (v > 2)is always greater than 1.

Suppose X is a normal random variable with mean 70 and standard deviation 3.Then P(X = 3)= ____________________.

Which of the following is not a characteristic for a normal distribution?

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

The value of an F distribution with v₁ = 6 and v₂ = 9 degrees of freedom such that the area to its right is 0.05 is 3.37.

Light Bulb Lifetime The lifetime of a light bulb (in hours)is exponentially distributed with $\lambda$ = 0.008. -{Light Bulb Lifetime Narrative} Find the probability that a light bulb will last between 120 and 140 hours.

What happens to the shape,mean,and variance of a c² distribution as the degrees of freedom increase?

Suppose X has a normal distribution with mean 40 and standard deviation 2.Shifting all the X values to the right 10 units results in a normal distribution with mean and standard deviation .

Suppose f(x)= 1/4 over the range a $\le$ x $\le$ b,and suppose P(X > 4)= 1/2.What are the values for a and b?