Question 1

Generally speaking,if two variables are unrelated,the covariance will be a number close to zero.

Accepted Answer

A) True 
 B)False  True

Question 2

The ____________________ measures the margin of relative change in the dependent variable.

Accepted Answer

slope

Question 3

In the equation of the least squares line, $$\hat { y } = b _ { 0 } + b _ { 1 } x$$ ,b0 is the ____________________ and b1 is the ____________________.

Accepted Answer

y-intercept;slope

Question 4

Longevity and Salary
A sample of eight observations of variables x (years of experience)and y (salary in $1,000s)is shown below:
 $$\begin{array} { | c | c c c c c c c c | } 
\hline \boldsymbol { x } & 5 & 3 & 7 & 9 & 2 & 4 & 6 & \mathbf { 8 } \
\hline y & 20 & 23 & 15 & 11 & 27 & 21 & 17 & 14 \
\hline
\end{array}$$
-{Longevity and Salary Narrative} Draw the scatter diagram and plot the least squares line.

Accepted Answer

The answer of Longevity and Salary
A sample of eight observations...

Question 5

Longevity and Salary
A sample of eight observations of variables x (years of experience)and y (salary in $1,000s)is shown below:
 $$\begin{array} { | c | c c c c c c c c | } 
\hline \boldsymbol { x } & 5 & 3 & 7 & 9 & 2 & 4 & 6 & \mathbf { 8 } \
\hline y & 20 & 23 & 15 & 11 & 27 & 21 & 17 & 14 \
\hline
\end{array}$$
-{Longevity and Salary Narrative} Determine the least squares line,and use it to estimate the value of y for x = 6.

Accepted Answer

@#LAT-DLM& .
When x

Question 6

When two variables x and y are linearly related,it does not necessarily mean that x ____________________ y.

Accepted Answer

The answer of When two variables x and y are...

Question 7

Assuming a linear relationship between X and Y,if the coefficient of correlation (r)equals -0.75,this means that:

Accepted Answer

A)  there is very weak correlation. 
B)  the slope b1 is = -0.75. 
C)  the value of X is always greater than the value of Y. 
D)  None of these choices are true. 
A)  there is very weak correlation. 
B)  the slope b1 is = -0.75. 
C)  the value of X is always greater than the value of Y. 
D)  None of these choices are true.

Question 8

If the coefficient of correlation r = $\pm$1,then the best-fit linear equation will actually include all of the observations.

Accepted Answer

A) True 
 B)False

Question 9

Generally speaking,if two variables are unrelated (as one increases,the other shows no pattern),the covariance will be:

Accepted Answer

A)  a large positive number. 
B)  a large negative number. 
C)  a positive or negative number close to zero. 
D)  None of these choices. 
A)  a large positive number. 
B)  a large negative number. 
C)  a positive or negative number close to zero. 
D)  None of these choices.

Question 10

Longevity and Salary
A sample of eight observations of variables x (years of experience)and y (salary in $1,000s)is shown below:
 $$\begin{array} { | c | c c c c c c c c | } 
\hline \boldsymbol { x } & 5 & 3 & 7 & 9 & 2 & 4 & 6 & \mathbf { 8 } \
\hline y & 20 & 23 & 15 & 11 & 27 & 21 & 17 & 14 \
\hline
\end{array}$$
-{Longevity and Salary Narrative}
a.
Calculate and interpret the covariance between x and y.
b.
Give a possible reason that the covariance is negative.

Accepted Answer

a.The sign indicates a negative relation

Question 11

If the coefficient of correlation r = 0,then there can be no relationship whatsoever between the dependent variable y and the independent variable x.

Accepted Answer

A) True 
 B)False

Question 12

Which of the following are measures of the linear relationship between two variables?

Accepted Answer

A)  The covariance 
B)  The coefficient of correlation 
C)  The variance 
D)  Both a and b 
A)  The covariance 
B)  The coefficient of correlation 
C)  The variance 
D)  Both a and b

Question 13

If the covariance of x and y is 26.16 and the standard deviation of x is 32.7,then the slope of the least squares line is b1 =.80.

Accepted Answer

A) True 
 B)False

Question 14

Which of the following is a property of r,the coefficient of correlation?

Accepted Answer

A)  r always lies between 0 and 1. 
B)  r has no units. 
C)  If you switch the values of X and Y,the sign of r changes. 
D)  All of these choices are true. 
A)  r always lies between 0 and 1. 
B)  r has no units. 
C)  If you switch the values of X and Y,the sign of r changes. 
D)  All of these choices are true.

Question 15

The method used to find the best fitting line through the observations is called the ____________________ method.

Accepted Answer

The answer of The method used to find the best...

Question 16

When the standard deviation is expressed as a percentage of the mean,the result is the coefficient of correlation.

Accepted Answer

A) True 
 B)False

Question 17

A perfect straight line sloping upward would produce a correlation coefficient value of 1.0.

Accepted Answer

A) True 
 B)False

Question 18

The coefficient of correlation r is a number that indicates the direction and the strength of the linear relationship between the dependent variable y and the independent variable x.

Accepted Answer

A) True 
 B)False

Question 19

The ____________________ of a linear relationship is hard to interpret from the covariance,but it is easy to interpret from the correlation.

Accepted Answer

The answer of The ____________________ of a linear relationship is...

Question 20

If the standard deviations of x and y are 12.5 and 10.8,respectively,and the covariance is 118.8,then the coefficient of correlation r is 0.88.

Accepted Answer

A) True 
 B)False

Exam 4: B: Numerical Descriptive Techniques

Generally speaking,if two variables are unrelated,the covariance will be a number close to zero.

The ____________________ measures the margin of relative change in the dependent variable.

In the equation of the least squares line, y^=b0+b1x\hat { y } = b _ { 0 } + b _ { 1 } xy^​=b0​+b1​x ,b0 is the ____________________ and b1 is the ____________________.

Longevity and Salary A sample of eight observations of variables x (years of experience)and y (salary in $1,000s)is shown below: 5 3 7 9 2 4 6 y 20 23 15 11 27 21 17 14 -{Longevity and Salary Narrative} Draw the scatter diagram and plot the least squares line.

Longevity and Salary A sample of eight observations of variables x (years of experience)and y (salary in $1,000s)is shown below: 5 3 7 9 2 4 6 y 20 23 15 11 27 21 17 14 -{Longevity and Salary Narrative} Determine the least squares line,and use it to estimate the value of y for x = 6.

When two variables x and y are linearly related,it does not necessarily mean that x ____________________ y.

Assuming a linear relationship between X and Y,if the coefficient of correlation (r)equals -0.75,this means that:

If the coefficient of correlation r = ±\pm± 1,then the best-fit linear equation will actually include all of the observations.

Generally speaking,if two variables are unrelated (as one increases,the other shows no pattern),the covariance will be:

If the coefficient of correlation r = 0,then there can be no relationship whatsoever between the dependent variable y and the independent variable x.

Which of the following are measures of the linear relationship between two variables?

If the covariance of x and y is 26.16 and the standard deviation of x is 32.7,then the slope of the least squares line is b1 =.80.

Which of the following is a property of r,the coefficient of correlation?

The method used to find the best fitting line through the observations is called the ____________________ method.

When the standard deviation is expressed as a percentage of the mean,the result is the coefficient of correlation.

A perfect straight line sloping upward would produce a correlation coefficient value of 1.0.

The coefficient of correlation r is a number that indicates the direction and the strength of the linear relationship between the dependent variable y and the independent variable x.

The ____________________ of a linear relationship is hard to interpret from the covariance,but it is easy to interpret from the correlation.

If the standard deviations of x and y are 12.5 and 10.8,respectively,and the covariance is 118.8,then the coefficient of correlation r is 0.88.

What Is Statistics

Graphical Descriptive Techniques I

Graphical Descriptive Techniques II

A: Numerical Descriptive Techniques

C: Numerical Descriptive Techniques

Data Collection and Sampling

Probability

A: Random Variables and Discrete Probability Distributions

B: Random Variables and Discrete Probability Distributions

Continuous 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

A: Simple Linear Regression and Correlation

B: Simple Linear Regression and Correlation

Multiple Regression

Model Building

Nonparametric Statistics

Time-Series Analysis and Forecasting

Statistical Process Control

Decision Analysis

Conclusion

Filters

In the equation of the least squares line, $\hat { y } = b _ { 0 } + b _ { 1 } x$ ,b₀ is the and b₁ is the .

If the coefficient of correlation r = $\pm$ 1,then the best-fit linear equation will actually include all of the observations.

If the covariance of x and y is 26.16 and the standard deviation of x is 32.7,then the slope of the least squares line is b₁ =.80.