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A direct relationship between an independent variable x and a dependent variably y means that the variables x and y increase or decrease together.

A) True
B) False

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In the first-order linear regression model, the population parameters of the y-intercept and the slope are:


A) b0b _ { 0 } and b1b _ { 1 } .
B) b0b _ { 0 } and β1\beta _ { 1 } .
C) β0\beta _ { 0 } and b1b _ { 1 } .
D) β0\beta _ { 0 } and β1\beta _ { 1 } .

E) All of the above
F) B) and C)

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Which of the following statements is correct when all the actual values of y are on an upward sloping regression line?


A) The coefficient of correlation is equal to one and the sign of the coefficient of correlation will be negative but the sign of the slope with be positive.
B) The coefficient of correlation and the slope must both be equal to 1.
C) The coefficient of correlation is equal to one and the sign of the coefficient of correlation and the sign of the slope will both be positive.
D) The coefficient of correlation and the slope must be equal to - 1.

E) All of the above
F) A) and B)

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The standard error of estimate, SεS _ { \varepsilon } , is given by:


A) SSE/(n - 2) .
B) SSE/(n2) \sqrt { S S E } / ( n - 2 ) .
C) SSE/(n2) \sqrt { S S E / ( n - 2 ) } .
D) SSE/ n2\sqrt { n - 2 } .

E) A) and B)
F) A) and C)

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A financier whose specialty is investing in movie productions has observed that, in general, movies with 'big-name' stars seem to generate more revenue than those movies whose stars are less well known. To examine his belief, he records the gross revenue and the payment (in $ million) given to the two highest-paid performers in the movie for 10 recently released movies.  Movie  Cost of two highest-  paid performers ($ m) Gross revenue ($ m)15.34827.26531.31841.82053.53162.62678.07382.42394.539106.758\begin{array} { | c | c | c | } \hline \text { Movie } & \begin{array} { c } \text { Cost of two highest- } \\\text { paid performers } ( \$ \mathrm {~m} )\end{array} & \begin{array} { c } \text { Gross revenue } \\( \$ \mathrm {~m} )\end{array} \\\hline 1 & 5.3 & 48 \\\hline 2 & 7.2 & 65 \\\hline 3 & 1.3 & 18 \\\hline 4 & 1.8 & 20 \\\hline 5 & 3.5 & 31 \\\hline 6 & 2.6 & 26 \\\hline 7 & 8.0 & 73 \\\hline 8 & 2.4 & 23 \\\hline 9 & 4.5 & 39 \\\hline 10 & 6.7 & 58 \\\hline\end{array} Assume that the conditions for the tests conducted in the previous two questions are not met. Do the data allow us to infer at the 5% significance level that payment to the two highest-paid performers and gross revenue are linearly related?

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H0 : blured image s = 0.
H1 : blured image s blured image 0.
Rejection...

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If all the points in a scatter diagram lie on the least squares regression line, then the coefficient of correlation must be:


A) 1.0.
B) -1.0.
C) either 1.0 or -1.0.
D) 0.0.

E) A) and C)
F) None of the above

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The method of least squares requires that the sum of the squared deviations between actual y values in the scatter diagram and y values predicted by the regression line be minimised.

A) True
B) False

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Which of the following best describes the relationship of the least squares regression line: Estimated y = 2 - x?


A) As x increases by 1 unit, y increases by 1 unit, estimated, on average.
B) As x increases by 1 unit y decreases by (2 -x) units, estimated, on average.
C) As x increases by 1 unit, y decreases by 1 unit, estimated, on average.
D) All of these choices are correct.

E) All of the above
F) A) and B)

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In regression analysis, if the coefficient of determination is 1.0, then:


A) the sum of squares for error must be 1.0.
B) the sum of squares for regression must be 1.0.
C) the sum of squares for error must be 0.0.
D) the sum of squares for regression must be 0.0.

E) A) and B)
F) A) and D)

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The Pearson coefficient of correlation r equals 1 when there is/are no:


A) explained variation.
B) unexplained variation.
C) y-intercept in the model.
D) outliers.

E) A) and B)
F) C) and D)

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Which of the following statements best describes why a linear regression is also called a least squares regression model?


A) A linear regression is also called a least squares regression model because the regression line is calculated by minimizing the square of the difference between each actual x data value and the predicted x value.
B) A linear regression is also called a least squares regression model because the regression line is calculated by minimizing the sum of the difference between each actual y data value and the predicted y value.
C) A linear regression is also called a least squares regression model because the regression line is calculated by minimizing the square of each actual y data value and the predicted y value.
D) why a A linear regression is also called a least squares regression model because the regression line is calculated by minimizing the sum of the square of the differences between each actual y data value and the predicted y value.

E) None of the above
F) B) and C)

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When the variance, σε2\sigma _ { \varepsilon } ^ { 2 } , of the error variable ε\varepsilon is a constant no matter what the value of x is, this condition is called:


A) homocausality.
B) heteroscedasticity.
C) homoscedasticity.
D) heterocausality.

E) A) and D)
F) None of the above

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The editor of a major academic book publisher claims that a large part of the cost of books is the cost of paper. This implies that larger books will cost more money. As an experiment to analyse the claim, a university student visits the bookstore and records the number of pages and the selling price of 12 randomly selected books. These data are listed below.  Book  Number of pages  Selling price ($) 1844552727503360354915605295306706507410408905539105865108655411677421291258\begin{array} { | c | c | c | } \hline \text { Book } & \text { Number of pages } & \text { Selling price (\$) } \\\hline 1 & 844 & 55 \\\hline 2 & 727 & 50 \\\hline 3 & 360 & 35 \\\hline 4 & 915 & 60 \\\hline 5 & 295 & 30 \\\hline 6 & 706 & 50 \\\hline 7 & 410 & 40 \\\hline 8 & 905 & 53 \\\hline 9 & 1058 & 65 \\\hline 10 & 865 & 54 \\\hline 11 & 677 & 42 \\\hline 12 & 912 & 58 \\\hline\end{array} Draw a scatter diagram of the data and plot the least squares regression line on it.

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A financier whose specialty is investing in movie productions has observed that, in general, movies with 'big-name' stars seem to generate more revenue than those movies whose stars are less well known. To examine his belief, he records the gross revenue and the payment (in $ million) given to the two highest-paid performers in the movie for 10 recently released movies.  Movie  Cost of two highest-  paid performers ($ m) Gross revenue ($ m)15.34827.26531.31841.82053.53162.62678.07382.42394.539106.758\begin{array} { | c | c | c | } \hline \text { Movie } & \begin{array} { c } \text { Cost of two highest- } \\\text { paid performers } ( \$ \mathrm {~m} )\end{array} & \begin{array} { c } \text { Gross revenue } \\( \$ \mathrm {~m} )\end{array} \\\hline 1 & 5.3 & 48 \\\hline 2 & 7.2 & 65 \\\hline 3 & 1.3 & 18 \\\hline 4 & 1.8 & 20 \\\hline 5 & 3.5 & 31 \\\hline 6 & 2.6 & 26 \\\hline 7 & 8.0 & 73 \\\hline 8 & 2.4 & 23 \\\hline 9 & 4.5 & 39 \\\hline 10 & 6.7 & 58 \\\hline\end{array} a. Determine the least squares regression line. b. Interpret the value of the slope of the regression line. c. Determine the standard error of estimate, and describe what this statistic tells you about the regression line.

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a. blured image blured image 4.225 + 8.285x
b. For eac...

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A professor of economics wants to study the relationship between income y (in $1000s) and education x (in years). A random sample of eight individuals is taken and the results are shown below.  Education 161115812101314 Income 5840553543415249\begin{array} { | l | c | c | c | c | c | c | c | c | } \hline \text { Education } & 16 & 11 & 15 & 8 & 12 & 10 & 13 & 14 \\\hline \text { Income } & 58 & 40 & 55 & 35 & 43 & 41 & 52 & 49 \\\hline\end{array} Conduct a test of the population slope to determine at the 5% significance level whether a linear relationship exists between years of education and income.

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blured image . blured image .
Rejection region: | t | ...

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A professor of economics wants to study the relationship between income y (in $1000s) and education x (in years). A random sample of eight individuals is taken and the results are shown below.  Education 161115812101314 Income 5840553543415249\begin{array} { | l | c | c | c | c | c | c | c | c | } \hline \text { Education } & 16 & 11 & 15 & 8 & 12 & 10 & 13 & 14 \\\hline \text { Income } & 58 & 40 & 55 & 35 & 43 & 41 & 52 & 49 \\\hline\end{array} Predict with 95% confidence the average income of all individuals with 10 years of education.

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39.715 ± 1...

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Pop-up coffee vendors have been popular in the city of Adelaide in 2013. A vendor is interested in knowing how temperature (in degrees Celsius) impacts daily hot coffee sales revenue (in $00's). A random sample of 6 days was taken, with the daily hot coffee sales revenue and the corresponding temperature of that day noted.  Coffee sales revenue  Temperature 6.502510.00175.50304.50353.504028.009\begin{array} { | c | c | } \hline \text { Coffee sales revenue } & \text { Temperature } \\\hline 6.50 & 25 \\\hline 10.00 & 17 \\\hline 5.50 & 30 \\\hline 4.50 & 35 \\\hline 3.50 & 40 \\\hline 28.00 & 9 \\\hline\end{array} a. Find the least squares regression line. b. Interpret the slope.

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blured image a. Estimated daily hot coffee sales rev...

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Given the data points (x,y) = (3,3) , (4,4) , (5,5) , (6,6) , (7,7) , the least squares estimates of the y-intercept and slope are respectively:


A) 0 and 1.
B) -1 and 0.
C) 5 and 5.
D) 5 and 0.

E) B) and C)
F) C) and D)

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The value of the sum of squares for regression, SSR, can never be larger than the value of sum of squares for error, SSE.

A) True
B) False

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Given the least squares regression line y-hat = 3.52 - 1.27x, and a coefficient of determination of 0.81, the coefficient of correlation is:


A) -0.85.
B) 0.85.
C) -0.90.
D) 0.90.

E) A) and C)
F) B) and C)

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