Question 1

Use the F table to find the following values of F.
a.F.01,12,20
b.F.05,20,40
c.F.025,5,15
d.F.01,8,30

Accepted Answer

a.3.23
b.1

Question 2

Use the t-table to find the following probabilities.
a.P(t8 > 2.306)
b.P(t80 > 2.639)
c.P(t24 > 1.711)
d.P(t35 > 1.306)

Accepted Answer

a.0.025
b.

Question 3

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 4

Suppose Lamont's exam score was at the 80th percentile on an exam whose mean was 90. What was Lamont's exam score?

Accepted Answer

A) 76.81 
B) 72.00 
C) 80.00 
D) Cannot tell without more information. 
A) 76.81 
B) 72.00 
C) 80.00 
D) Cannot tell without more information.

Question 5

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

Accepted Answer

A) True 
 B)False

Question 6

What number corresponds to F.025,3,5?

Accepted Answer

A) 14.88 
B) 7.76 
C) 12.06 
D) 5.41 
A) 14.88 
B) 7.76 
C) 12.06 
D) 5.41

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 between 80 and 90?

Accepted Answer

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

Question 8

The variance of a Student t distribution approaches zero as the degrees of freedom approaches infinity.

Accepted Answer

A) True 
 B)False

Question 9

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 10

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 11

Suppose X has an exponential distribution with mean 2. Find f(x).

Accepted Answer

f(x) = 0.5

Question 12

Continuous probability distributions describe probabilities associated with random variables that are able to assume any finite number of values along an interval.

Accepted Answer

A) True 
 B)False

Question 13

A continuous random variable X has a uniform distribution between 5 and 25 (inclusive), then P(X = 15) = 0.05.

Accepted Answer

A) True 
 B)False

Question 14

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 proportion of callers are put on hold longer than 3 minutes?

Accepted Answer

P(X > 3) =

Question 15

Which of the following has a mean and variance that depend on degrees of freedom?

Accepted Answer

A) Student t 
B) $\chi$2 
C) F 
D) All of these choices are true. 
A) Student t 
B) $\chi$2 
C) F 
D) All of these choices are true.

Question 16

A standard normal distribution is a normal distribution with:

Accepted Answer

A) a mean of zero and a standard deviation of one. 
B) a mean of one and a standard deviation of zero. 
C) a mean always larger than the standard deviation. 
D) None of these choices. 
A) a mean of zero and a standard deviation of one. 
B) a mean of one and a standard deviation of zero. 
C) a mean always larger than the standard deviation. 
D) None of these choices.

Question 17

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 18

The value of a chi-squared distribution with 5 degrees of freedom such that the area to its left is 0.10 is 1.61.

Accepted Answer

A) True 
 B)False

Question 19

If the random variable X is exponentially distributed with parameter $\lambda$ = 0.05, then the probability P(X > 20) = 0.3679.

Accepted Answer

A) True 
 B)False

Question 20

Suppose X has an F distribution. Which of the following is true?

Accepted Answer

A) f(x) is symmetrical. 
B) All the values of X are non-negative. 
C) The mean of X is zero. 
D) All of these choices. 
A) f(x) is symmetrical. 
B) All the values of X are non-negative. 
C) The mean of X is zero. 
D) All of these choices.

Use the F table to find the following values of F. a.F_.01,12,20 b.F_.05,20,40 c.F_.025,5,15 d.F_.01,8,30

Use the t-table to find the following probabilities. a.P(t₈ > 2.306) b.P(t₈₀ > 2.639) c.P(t₂₄ > 1.711) d.P(t₃₅ > 1.306)

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.

Suppose Lamont's exam score was at the 80^th percentile on an exam whose mean was 90. What was Lamont's exam score?

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

What number corresponds to F_.025,3,5?

The variance of a Student t distribution approaches zero as the degrees of freedom approaches infinity.

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?

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

Suppose X has an exponential distribution with mean 2. Find f(x).

Continuous probability distributions describe probabilities associated with random variables that are able to assume any finite number of values along an interval.

A continuous random variable X has a uniform distribution between 5 and 25 (inclusive), then P(X = 15) = 0.05.

Which of the following has a mean and variance that depend on degrees of freedom?

A standard normal distribution is a normal distribution with:

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

The value of a chi-squared distribution with 5 degrees of freedom such that the area to its left is 0.10 is 1.61.

If the random variable X is exponentially distributed with parameter $\lambda$ = 0.05, then the probability P(X > 20) = 0.3679.

Suppose X has an F distribution. Which of the following is true?

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

Use the F table to find the following values of F. a.F.01,12,20 b.F.05,20,40 c.F.025,5,15 d.F.01,8,30

Use the t-table to find the following probabilities. a.P(t8 > 2.306) b.P(t80 > 2.639) c.P(t24 > 1.711) d.P(t35 > 1.306)

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.

Suppose Lamont's exam score was at the 80th percentile on an exam whose mean was 90. What was Lamont's exam score?

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

What number corresponds to F.025,3,5?

The variance of a Student t distribution approaches zero as the degrees of freedom approaches infinity.

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?

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

Suppose X has an exponential distribution with mean 2. Find f(x).

Continuous probability distributions describe probabilities associated with random variables that are able to assume any finite number of values along an interval.

A continuous random variable X has a uniform distribution between 5 and 25 (inclusive), then P(X = 15) = 0.05.

Which of the following has a mean and variance that depend on degrees of freedom?

A standard normal distribution is a normal distribution with:

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

The value of a chi-squared distribution with 5 degrees of freedom such that the area to its left is 0.10 is 1.61.

If the random variable X is exponentially distributed with parameter λ\lambdaλ = 0.05, then the probability P(X > 20) = 0.3679.

Suppose X has an F distribution. Which of the following is true?

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

Use the F table to find the following values of F. a.F_.01,12,20 b.F_.05,20,40 c.F_.025,5,15 d.F_.01,8,30

Use the t-table to find the following probabilities. a.P(t₈ > 2.306) b.P(t₈₀ > 2.639) c.P(t₂₄ > 1.711) d.P(t₃₅ > 1.306)

Suppose Lamont's exam score was at the 80^th percentile on an exam whose mean was 90. What was Lamont's exam score?

What number corresponds to F_.025,3,5?

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?

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

If the random variable X is exponentially distributed with parameter $\lambda$ = 0.05, then the probability P(X > 20) = 0.3679.