Question 1

Z.025 is the value of Z such that the area to the ____________________ of Z is .9750.

Accepted Answer

Question 2

What number corresponds to t0.05,10?

Accepted Answer

A)  1.812 
B)  1.372 
C)  2.228 
D)  1.833 
A)  1.812 
B)  1.372 
C)  2.228 
D)  1.833

Question 3

If X is a continuous random variable on the interval [0, 10], then P(X = 5) = f(5) = 1/10.

Accepted Answer

A) True 
 B)False

Question 4

If X has an exponential distribution with parameter $\lambda$, then the mean of X is ______________.

Accepted Answer

The answer of If X has an exponential distribution with...

Question 5

The variance of a Student t distribution approaches ____________________ as the degrees of freedom increase to infinity.

Accepted Answer

The answer of The variance of a Student t distribution...

Question 6

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 7

Which of the following represents a difference between continuous and discrete random variables?

Accepted Answer

A)  Continuous random variables assume an uncountable number of values, and discrete random variables do not. 
B)  The probability for any individual value of a continuous random variable is zero, but for discrete random variables it is not. 
C)  Probability for continuous random variables means finding the area under a curve, while for discrete random variables it means summing individual probabilities. 
D)  All of these choices are true. 
A)  Continuous random variables assume an uncountable number of values, and discrete random variables do not. 
B)  The probability for any individual value of a continuous random variable is zero, but for discrete random variables it is not. 
C)  Probability for continuous random variables means finding the area under a curve, while for discrete random variables it means summing individual probabilities. 
D)  All of these choices are true.

Question 8

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 9

Which of the following distributions is not skewed?

Accepted Answer

A)  Student t 
B)   
C)  F 
D)  All of these distributions are skewed. 
A)  Student t 
B)   
C)  F 
D)  All of these distributions are skewed.

Question 10

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.
20

Question 11

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 less than $1,000?

Accepted Answer

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

Question 12

The Student t distribution:

Accepted Answer

A)  is symmetrical. 
B)  approaches the normal distribution as the degrees of freedom increase. 
C)  has more area in the tails than the standard normal distribution does. 
D)  All of these choices are true. 
A)  is symmetrical. 
B)  approaches the normal distribution as the degrees of freedom increase. 
C)  has more area in the tails than the standard normal distribution does. 
D)  All of these choices are true.

Question 13

We standardize a random variable by subtracting its ____________________ and dividing by its ____________________.

Accepted Answer

mean; stan

Question 14

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 15

The variance of a   distribution is twice the value of its mean.

Accepted Answer

A) True 
 B)False

Question 16

A random variable with density function 0.01e-x/100 for x$\ge$ 0 has an exponential distribution whose mean is ____________________.

Accepted Answer

Question 17

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 has...

Question 18

The value of a chi-squared distribution with 8 degrees of freedom such that the area to its left is 0.95 is 2.73.

Accepted Answer

A) True 
 B)False

Question 19

In its standardized form, the normal distribution:

Accepted Answer

A)  has a mean of 0 and a standard deviation of 1. 
B)  has a mean of 1 and a variance of 0. 
C)  has an area equal to 0.5. 
D)  cannot be used to approximate discrete probability distributions. 
A)  has a mean of 0 and a standard deviation of 1. 
B)  has a mean of 1 and a variance of 0. 
C)  has an area equal to 0.5. 
D)  cannot be used to approximate discrete probability distributions.

Question 20

Subway Waiting Time
At a subway station the waiting time for a subway is found to be uniformly distributed between 1 and 5 minutes.
-{Subway Waiting Time Narrative} What is the probability density function for this uniform distribution?

Accepted Answer

The answer of Subway Waiting Time
At a subway station the...

Z_.025 is the value of Z such that the area to the ____________________ of Z is .9750.

What number corresponds to t_0.05,10?

If X is a continuous random variable on the interval [0, 10], then P(X = 5) = f(5) = 1/10.

If X has an exponential distribution with parameter $\lambda$ , then the mean of X is ______________.

The variance of a Student t distribution approaches ____________________ as the degrees of freedom increase to infinity.

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

Which of the following represents a difference between continuous and discrete random variables?

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

Which of the following distributions is not skewed?

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.

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 less than $1,000?

The Student t distribution:

We standardize a random variable by subtracting its and dividing by its .

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

The variance of a distribution is twice the value of its mean.

A random variable with density function 0.01e^-x/100for x $\ge$ 0 has an exponential distribution whose mean is ____________________.

The value of a chi-squared distribution with 8 degrees of freedom such that the area to its left is 0.95 is 2.73.

In its standardized form, the normal distribution:

Subway Waiting Time At a subway station the waiting time for a subway is found to be uniformly distributed between 1 and 5 minutes. -{Subway Waiting Time Narrative} What is the probability density function for this uniform distribution?

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

Simple Linear Regression and Correlation

Multiple Regression

Filters

Exam 8: Continuous Probability Distributions

Z.025 is the value of Z such that the area to the ____________________ of Z is .9750.

What number corresponds to t0.05,10?

If X is a continuous random variable on the interval [0, 10], then P(X = 5) = f(5) = 1/10.

If X has an exponential distribution with parameter λ\lambdaλ , then the mean of X is ______________.

The variance of a Student t distribution approaches ____________________ as the degrees of freedom increase to infinity.

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

Which of the following represents a difference between continuous and discrete random variables?

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

Which of the following distributions is not skewed?

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.

The Student t distribution:

We standardize a random variable by subtracting its ____________________ and dividing by its ____________________.

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

The variance of a distribution is twice the value of its mean.

A random variable with density function 0.01e-x/100 for x ≥\ge≥ 0 has an exponential distribution whose mean is ____________________.

The value of a chi-squared distribution with 8 degrees of freedom such that the area to its left is 0.95 is 2.73.

In its standardized form, the normal distribution:

Subway Waiting Time At a subway station the waiting time for a subway is found to be uniformly distributed between 1 and 5 minutes. -{Subway Waiting Time Narrative} What is the probability density function for this uniform distribution?

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

Simple Linear Regression and Correlation

Multiple Regression

Filters

Z_.025 is the value of Z such that the area to the ____________________ of Z is .9750.

What number corresponds to t_0.05,10?

If X has an exponential distribution with parameter $\lambda$ , then the mean of X is ______________.

We standardize a random variable by subtracting its and dividing by its .

A random variable with density function 0.01e^-x/100for x $\ge$ 0 has an exponential distribution whose mean is ____________________.