Question 1

In the standard normal distribution, z0.05 = 1.645 means that 5% of all values of z are below 1.645 and 95% are above it.

Accepted Answer

A) True 
 B)False

Question 2

If the random variable X is exponentially distributed with parameter $\lambda$ = 0.05, then the probability P(X < 5) = .2865.

Accepted Answer

A) True 
 B)False

Question 3

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 4

Stacy took a math test whose mean was 70 and standard deviation was 5. The total points possible was 100. Stacey's results were reported to be at the 95th percentile. What was Stacey's actual exam score, rounded to the nearest whole number?

Accepted Answer

A) 95 
B) 78 
C) 75 
D) 62 
A) 95 
B) 78 
C) 75 
D) 62

Question 5

If your golf score is 3 standard deviations below the mean, its corresponding value on the Z distribution is -3.

Accepted Answer

A) True 
 B)False

Question 6

NARRBEGIN: Waiting Time
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.NARREND
-{Waiting Time Narrative} What is the probability that a patient would have to wait no more than one hour?

Accepted Answer

The answer of NARRBEGIN: Waiting Time
Waiting Time
The length of time...

Question 7

NARRBEGIN: Calculus Scores
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.)
NARREND
-{Calculus Scores Narrative} What is the probability that a randomly selected student will have a score of 94 or lower?

Accepted Answer

The answer of NARRBEGIN: Calculus Scores
Calculus Scores
Scores of high school...

Question 8

NARRBEGIN: Phone Orders
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.NARREND
-{Phone Orders Narrative} What is the probability that a randomly selected caller is placed on hold for fewer than 6 minutes?

Accepted Answer

P(X < 6) =

Question 9

Suppose f(x) = 0.25. What range of possible values can X take on and still have the density function be legitimate?

Accepted Answer

A) [0, 4] 
B) [4, 8] 
C) [-2, +2] 
D) All of these choices are true. 
A) [0, 4] 
B) [4, 8] 
C) [-2, +2] 
D) All of these choices are true.

Question 10

Suppose you have a X2 distribution with 20 degrees of freedom.
a.Find the mean.
b.Find the variance.
c.Find the standard deviation.

Accepted Answer

Question 11

For values of degrees of freedom greater than 100, the X2 distribution can be approximated by a(n) ____________________ distribution.

Accepted Answer

Question 12

NARRBEGIN: Waiting Time
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.NARREND
-The time required to complete a particular assembly operation has a uniform distribution between 25 and 50 minutes.
a.What is the probability density function for this uniform distribution?
b.What is the probability that the assembly operation will require more than 40 minutes to complete?
c.Suppose more time was allowed to complete the operation, and the values of X were extended to the range from 25 to 60 minutes. What would f(x) be in this case?

Accepted Answer

a.f(x) = 1/25, 25 @#LAT-DLM& x

Question 13

NARRBEGIN: Phone Orders
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.NARREND
-{Phone Orders Narrative} What is the value of $\lambda$ the parameter of the exponential distribution in this situation?

Accepted Answer

The answer of NARRBEGIN: Phone Orders
Phone Orders
The L. L. Bean...

Question 14

NARRBEGIN: ElectronicsTest
Electronics Test
The time it takes a student to finish a electronics test has a uniform distribution between 50 and 70 minutes.NARREND
-{Electronics Test Narrative} What is the mean amount of time it takes a student to finish the test?

Accepted Answer

The answer of NARRBEGIN: ElectronicsTest
Electronics Test
The time it takes a...

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

NARRBEGIN: Repair Time
Repair Time
The time it takes a technician to fix a telephone problem is exponentially distributed with a mean of 15 minutes.NARREND
-{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 NARRBEGIN: Repair Time
Repair Time
The time it takes...

Question 17

The expected value of the Student t distribution is zero.

Accepted Answer

A) True 
 B)False

Question 18

If the mean of an exponential distribution is 2, then the value of the parameter $\lambda$ is

Accepted Answer

A) 0 
B) 2.0 
C) 0.5 
D) 1.0 
A) 0 
B) 2.0 
C) 0.5 
D) 1.0

Question 19

A larger standard deviation of a normal distribution indicates that the distribution becomes:

Accepted Answer

A) narrower and more peaked. 
B) flatter and wider. 
C) more skewed to the right. 
D) more skewed to the left. 
A) narrower and more peaked. 
B) flatter and wider. 
C) more skewed to the right. 
D) more skewed to the left.

Question 20

The Student t distribution looks similar in shape to a standard normal distribution, except it is not as widely spread.

Accepted Answer

A) True 
 B)False

In the standard normal distribution, z_0.05 = 1.645 means that 5% of all values of z are below 1.645 and 95% are above it.

If the random variable X is exponentially distributed with parameter $\lambda$ = 0.05, then the probability P(X < 5) = .2865.

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.

Stacy took a math test whose mean was 70 and standard deviation was 5. The total points possible was 100. Stacey's results were reported to be at the 95th percentile. What was Stacey's actual exam score, rounded to the nearest whole number?

If your golf score is 3 standard deviations below the mean, its corresponding value on the Z distribution is -3.

Suppose f(x) = 0.25. What range of possible values can X take on and still have the density function be legitimate?

Suppose you have a X² distribution with 20 degrees of freedom. a.Find the mean. b.Find the variance. c.Find the standard deviation.

For values of degrees of freedom greater than 100, the X² distribution can be approximated by a(n) ____________________ distribution.

NARRBEGIN: ElectronicsTest Electronics Test The time it takes a student to finish a electronics test has a uniform distribution between 50 and 70 minutes.NARREND -{Electronics Test Narrative} What is the mean amount of time it takes a student to finish the test?

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 .

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

The expected value of the Student t distribution is zero.

If the mean of an exponential distribution is 2, then the value of the parameter $\lambda$ is

A larger standard deviation of a normal distribution indicates that the distribution becomes:

The Student t distribution looks similar in shape to a standard normal distribution, except it is not as widely spread.

What Is Statistics

Graphical Descriptive Techniques I

Graphical Descriptive Techniques II

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 Optional

Simple Linear Regression and Correlation

Multiple Regression

Filters

Exam 8: Continuous Probability Distributions

In the standard normal distribution, z0.05 = 1.645 means that 5% of all values of z are below 1.645 and 95% are above it.

If the random variable X is exponentially distributed with parameter λ\lambdaλ = 0.05, then the probability P(X < 5) = .2865.

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.

Stacy took a math test whose mean was 70 and standard deviation was 5. The total points possible was 100. Stacey's results were reported to be at the 95th percentile. What was Stacey's actual exam score, rounded to the nearest whole number?

If your golf score is 3 standard deviations below the mean, its corresponding value on the Z distribution is -3.

Suppose f(x) = 0.25. What range of possible values can X take on and still have the density function be legitimate?

Suppose you have a X2 distribution with 20 degrees of freedom. a.Find the mean. b.Find the variance. c.Find the standard deviation.

For values of degrees of freedom greater than 100, the X2 distribution can be approximated by a(n) ____________________ distribution.

NARRBEGIN: ElectronicsTest Electronics Test The time it takes a student to finish a electronics test has a uniform distribution between 50 and 70 minutes.NARREND -{Electronics Test Narrative} What is the mean amount of time it takes a student to finish the test?

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 ____________________.

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

The expected value of the Student t distribution is zero.

If the mean of an exponential distribution is 2, then the value of the parameter λ\lambdaλ is

A larger standard deviation of a normal distribution indicates that the distribution becomes:

The Student t distribution looks similar in shape to a standard normal distribution, except it is not as widely spread.

What Is Statistics

Graphical Descriptive Techniques I

Graphical Descriptive Techniques II

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 Optional

Simple Linear Regression and Correlation

Multiple Regression

Filters

In the standard normal distribution, z_0.05 = 1.645 means that 5% of all values of z are below 1.645 and 95% are above it.

If the random variable X is exponentially distributed with parameter $\lambda$ = 0.05, then the probability P(X < 5) = .2865.

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.

Suppose you have a X² distribution with 20 degrees of freedom. a.Find the mean. b.Find the variance. c.Find the standard deviation.

For values of degrees of freedom greater than 100, the X² distribution can be approximated by a(n) ____________________ 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 .

If the mean of an exponential distribution is 2, then the value of the parameter $\lambda$ is