Question 1

If the value of Z is z = 99,that means you are at the 99th percentile on the Z distribution.

Accepted Answer

A) True 
 B)False

Question 2

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 3

The exponential distribution is suitable to model the length of time that elapses before the first telephone call is received by a switchboard.

Accepted Answer

A) True 
 B)False

Question 4

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 probability that a randomly selected caller is placed on hold for 3 to 6 minutes?

Accepted Answer

P(3 < X <

Question 5

Repair Time 
The time it takes a technician to fix a telephone problem is exponentially distributed with a mean of 15 minutes. ​ ​
-{Repair Time Narrative} What is the probability density function for the time it takes a technician to fix a telephone problem?

Accepted Answer

f(x)= (1/1

Question 6

The value of χ2 with v degrees of freedom such that the area to its right under the chi-squared curve is equal to A is denoted by   ,while   denotes the value such that the area to its left is A.

Accepted Answer

A) True 
 B)False

Question 7

Given that Z is a standard normal variable,the variance of Z:

Accepted Answer

A) is always greater than 2.0. 
B) is always greater than 1.0. 
C) is always equal to 1.0. 
D) cannot assume a specific value. 
A) is always greater than 2.0. 
B) is always greater than 1.0. 
C) is always equal to 1.0. 
D) cannot assume a specific value.

Question 8

P(Z > 3.00)is approximately ____________________.

Accepted Answer

The answer of P(Z > 3.00)is approximately ____________________....

Question 9

The mean of the standard normal distribution is ____________________ and the standard deviation is ____________________.

Accepted Answer

The answer of The mean of the standard normal distribution...

Question 10

The probability density function,f(x),for any continuous random variable X,represents:

Accepted Answer

A) all possible values that X will assume within some interval a ≤ x ≤ b 
B)  the probability that X takes on a specific value x. 
C) The height of the density function at x. 
D)  None of these choices. 
A) all possible values that X will assume within some interval a ≤ x ≤ b 
B)  the probability that X takes on a specific value x. 
C) The height of the density function at x. 
D)  None of these choices.

Question 11

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 12

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 13

A national standardized testing company can tell you your relative standing on an exam without divulging the mean or the standard deviation of the exam scores.

Accepted Answer

A) True 
 B)False

Question 14

Diet 
Researchers studying the effects of a new diet found that the weight loss over a one-month period by those on the diet was normally distributed with a mean of 10 pounds and a standard deviation of 5 pounds. ​ ​
-{Diet Narrative} What proportion of the dieters gained weight?

Accepted Answer

The answer of  Diet 
Researchers studying the effects of...

Question 15

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.

Question 16

The Student t distribution with parameter v = 4 has a variance V(t)equal to:

Accepted Answer

A) 4 
B) 0 
C) 2 
D) 1 
A) 4 
B) 0 
C) 2 
D) 1

Question 17

P(1 < Z < 2)= P(Z < 2)− ____________________.

Accepted Answer

The answer of P(1 < Z < 2)= P(Z <...

Question 18

A continuous random variable X has a uniform distribution between 10 and 20 (inclusive),then the probability that X falls between 12 and 15 is 0.30.

Accepted Answer

A) True 
 B)False

Question 19

If the random variable X is exponentially distributed with parameter λ = 1.5,then the probability P(2 ≤ X ≤ 4),up to 4 decimal places,is

Accepted Answer

A) 0.6667 
B) 0.0473 
C) 0.5000 
D) 0.2500 
A) 0.6667 
B) 0.0473 
C) 0.5000 
D) 0.2500

Question 20

The shape of the density function for an exponential distribution is ____________________.

Accepted Answer

skewed 
po

Exam 8: Continuous Probability Distributions

If the value of Z is z = 99,that means you are at the 99th percentile on the Z distribution.

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

The exponential distribution is suitable to model the length of time that elapses before the first telephone call is received by a switchboard.

Repair Time The time it takes a technician to fix a telephone problem is exponentially distributed with a mean of 15 minutes. ​ ​ -{Repair Time Narrative} What is the probability density function for the time it takes a technician to fix a telephone problem?

The value of χ2 with v degrees of freedom such that the area to its right under the chi-squared curve is equal to A is denoted by ,while denotes the value such that the area to its left is A.

Given that Z is a standard normal variable,the variance of Z:

P(Z > 3.00)is approximately ____________________.

The mean of the standard normal distribution is ____________________ and the standard deviation is ____________________.

The probability density function,f(x),for any continuous random variable X,represents:

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

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?

A national standardized testing company can tell you your relative standing on an exam without divulging the mean or the standard deviation of the exam scores.

Diet Researchers studying the effects of a new diet found that the weight loss over a one-month period by those on the diet was normally distributed with a mean of 10 pounds and a standard deviation of 5 pounds. ​ ​ -{Diet Narrative} What proportion of the dieters gained weight?

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

The Student t distribution with parameter v = 4 has a variance V(t)equal to:

P(1 < Z < 2)= P(Z < 2)− ____________________.

A continuous random variable X has a uniform distribution between 10 and 20 (inclusive),then the probability that X falls between 12 and 15 is 0.30.

If the random variable X is exponentially distributed with parameter λ = 1.5,then the probability P(2 ≤ X ≤ 4),up to 4 decimal places,is

The shape of the density function for an exponential distribution is ____________________.

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

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

Repair Time The time it takes a technician to fix a telephone problem is exponentially distributed with a mean of 15 minutes. -{Repair Time Narrative} What is the probability density function for the time it takes a technician to fix a telephone problem?

The value of χ² with v degrees of freedom such that the area to its right under the chi-squared curve is equal to A is denoted by ,while denotes the value such that the area to its left is A.

The mean of the standard normal distribution is and the standard deviation is .

Diet Researchers studying the effects of a new diet found that the weight loss over a one-month period by those on the diet was normally distributed with a mean of 10 pounds and a standard deviation of 5 pounds. -{Diet Narrative} What proportion of the dieters gained weight?