Question 1

The shape of an F distribution is ____________________.

Accepted Answer

positively

Question 2

We distinguish between discrete and continuous random variables by noting whether the number of possible values is countable or uncountable.

Accepted Answer

A) True 
 B)False

Question 3

If P(t > t.01,v)= 2.50,then the number of degrees of freedom v is:

Accepted Answer

A) 20 
B) 21 
C) 22 
D) 23 
A) 20 
B) 21 
C) 22 
D) 23

Question 4

What is the mode of the standard normal distribution?
a.0 (because the distribution is symmetric,mean=median=mode)
b.−1
c.1
d.2

Accepted Answer

The answer of What is the mode of the standard...

Question 5

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

Accepted Answer

A) True 
 B)False

Question 6

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 7

Let X represent weekly income expressed in dollars.Since there is no set upper limit,we cannot identify (and thus cannot count)all the possible values.Consequently,weekly income is regarded as a continuous random variable.

Accepted Answer

A) True 
 B)False

Question 8

Suppose you have a Student t distribution with 20 degrees of freedom.
a.Find the mean.
b.Find the variance.
c.Find the standard deviation.

Accepted Answer

a. 0 
b. 2

Question 9

If X is a continuous random variable on the interval [0,10],then P(X > 5)= P(X ≥ 5).

Accepted Answer

A) True 
 B)False

Question 10

Counter Sales
suppose that customers arrive at a counter at an avarage rate of three customers per minute and their arrivals follow the poisson model.
-{Counter Sales Narrative} Use the appropriate exponential distribution to find the probability that the next customer will not arrive within the next 2 minutes.

Accepted Answer

The answer of Counter Sales
suppose that customers arrive at a...

Question 11

Given that Z is a standard normal random variable,a negative value (z)on its distribution would indicate:

Accepted Answer

A) z is to the left of the mean. 
B) the standard deviation of this Z distribution is negative. 
C) the area between zero and the value z is negative. 
D) None of these choices. 
A) z is to the left of the mean. 
B) the standard deviation of this Z distribution is negative. 
C) the area between zero and the value z is negative. 
D) None of these choices.

Question 12

Which of the following does not represent a continuous uniform random variable?

Accepted Answer

A) f(x)= 1/2 for x between −1 and 1,inclusive. 
B) f(x)= 10 for x between 0 and 1/10,inclusive. 
C) f(x)= 1/3 for x = 4,5,6. 
D) None of these choices represents a continuous uniform random variable. 
A) f(x)= 1/2 for x between −1 and 1,inclusive. 
B) f(x)= 10 for x between 0 and 1/10,inclusive. 
C) f(x)= 1/3 for x = 4,5,6. 
D) None of these choices represents a continuous uniform random variable.

Question 13

Battery Life
 A certain brand of batteries has a lifetime that has a normal distribution with a mean of 3,750 hours and a standard deviation of 300 hours. ​ ​
-{Battery Life Narrative} What lifetime should the manufacturer advertise for these batteries in order that only 2% of the lamps will wear out before the advertised lifetime?

Accepted Answer

The answer of Battery Life
 A certain brand of batteries...

Question 14

What proportion of the data from a normal distribution is within two standard deviations from the mean?

Accepted Answer

A) 0.3413 
B) 0.4772 
C) 0.6826 
D) 0.9544 
A) 0.3413 
B) 0.4772 
C) 0.6826 
D) 0.9544

Question 15

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 16

What is the mean of the standard normal distribution?
a.0
b.−1
c.1
d.2

Accepted Answer

The answer of What is the mean of the standard...

Question 17

If the random variable X is exponentially distributed with parameter λ = 2,then the probability that X is between 1 and 2 equals the probability that X is between 2 and 3.

Accepted Answer

A) True 
 B)False

Question 18

What is the median of the standard normal distribution?
a.1
b.−1
c.0 (because the distribution is symmetric,mean=median=mode)
d.2

Accepted Answer

The answer of What is the median of the standard...

Question 19

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 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 is the value of λ,the parameter of the exponential distribution in this situation?

Accepted Answer

The answer of Phone Orders
 The L.L.Bean catalog department that...

The shape of an F distribution is ____________________.

We distinguish between discrete and continuous random variables by noting whether the number of possible values is countable or uncountable.

If P(t > t_.01,_v)= 2.50,then the number of degrees of freedom v is:

What is the mode of the standard normal distribution? a.0 (because the distribution is symmetric,mean=median=mode) b.−1 c.1 d.2

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

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.

Let X represent weekly income expressed in dollars.Since there is no set upper limit,we cannot identify (and thus cannot count)all the possible values.Consequently,weekly income is regarded as a continuous random variable.

Suppose you have a Student t distribution with 20 degrees of freedom. a.Find the mean. b.Find the variance. c.Find the standard deviation.

If X is a continuous random variable on the interval [0,10],then P(X > 5)= P(X ≥ 5).

Given that Z is a standard normal random variable,a negative value (z)on its distribution would indicate:

Which of the following does not represent a continuous uniform random variable?

What proportion of the data from a normal distribution is within two standard deviations from the mean?

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 .

What is the mean of the standard normal distribution? a.0 b.−1 c.1 d.2

If the random variable X is exponentially distributed with parameter λ = 2,then the probability that X is between 1 and 2 equals the probability that X is between 2 and 3.

What is the median of the standard normal distribution? a.1 b.−1 c.0 (because the distribution is symmetric,mean=median=mode) d.2

The exponential density function f(x):

What Is Statistics

Graphical Descriptive Techniques 1

Graphical Descriptive Techniques 2

Numerical Descriptive Techniques

Data Collection and Sampling

Probability

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

Simple Linear Regression and Correlation

Multiple Regression

Model Building

Nonparametric Statistics

Time-Series Analytics and Forecasting

Statistical Process Control

Decision Analysis

Conclusion

Filters

Exam 8: Continuous Probability Distributions

The shape of an F distribution is ____________________.

We distinguish between discrete and continuous random variables by noting whether the number of possible values is countable or uncountable.

If P(t > t.01,v)= 2.50,then the number of degrees of freedom v is:

What is the mode of the standard normal distribution? a.0 (because the distribution is symmetric,mean=median=mode) b.−1 c.1 d.2

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

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.

Let X represent weekly income expressed in dollars.Since there is no set upper limit,we cannot identify (and thus cannot count)all the possible values.Consequently,weekly income is regarded as a continuous random variable.

Suppose you have a Student t distribution with 20 degrees of freedom. a.Find the mean. b.Find the variance. c.Find the standard deviation.

If X is a continuous random variable on the interval [0,10],then P(X > 5)= P(X ≥ 5).

Given that Z is a standard normal random variable,a negative value (z)on its distribution would indicate:

Which of the following does not represent a continuous uniform random variable?

What proportion of the data from a normal distribution is within two standard deviations from the mean?

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 ____________________.

What is the mean of the standard normal distribution? a.0 b.−1 c.1 d.2

If the random variable X is exponentially distributed with parameter λ = 2,then the probability that X is between 1 and 2 equals the probability that X is between 2 and 3.

What is the median of the standard normal distribution? a.1 b.−1 c.0 (because the distribution is symmetric,mean=median=mode) d.2

The exponential density function f(x):

What Is Statistics

Graphical Descriptive Techniques 1

Graphical Descriptive Techniques 2

Numerical Descriptive Techniques

Data Collection and Sampling

Probability

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

Simple Linear Regression and Correlation

Multiple Regression

Model Building

Nonparametric Statistics

Time-Series Analytics and Forecasting

Statistical Process Control

Decision Analysis

Conclusion

Filters

If P(t > t_.01,_v)= 2.50,then the number of degrees of freedom v is:

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 .