Question 1

The standard error of estimate is the square root of the unexplained variation.

Accepted Answer

A) True 
 B)False

Question 2

A psychologist wants to determine if there is a linear relationship between the number of hours a person goes without sleep and the number of mistakes he/she makes on a simple test. The following data is recorded. Determine the equation of the regression line and graph the line on a scatter plot .
$\begin{array}{ll}
\text { Hours without Sleep, } x & \text { Number of Mistakes, } \
32 & 6 \
38 & 8 \
48 & 13 \
24 & 5 \
46 & 7 \
35 & 6 \
30 & 5 \
34 & 8 \
42 & 12
\end{array}$

Accepted Answer

The answer of A psychologist wants to determine if there...

Question 3

$$\begin{array}{l}
\text { Compute the slope of the regression line for the data }\
\begin{array} { l c c c c c c } 
& \text { X values } & - 3 & - 1 & 2 & 5 & 10 \
\text { below. } & \text { Y values } & 5 & 4 & - 2 & 4 & - 3
\end{array}
\end{array}$$

Accepted Answer

A)  -0.51 
B)  -1.43 
C)  1.01 
D)  -3.37 
A)  -0.51 
B)  -1.43 
C)  1.01 
D)  -3.37

Question 4

Compute the intercept of the regression line for the data below. 
$\begin{array}{cccc}
\mathrm{X} \text { values } & -3 & 0 & 6 \
\mathrm{Y} \text { values } & 6 & 5 & -2
\end{array}$

Accepted Answer

A)  0.71 
B)  3.72 
C)  3.93 
D)  9.32 
A)  0.71 
B)  3.72 
C)  3.93 
D)  9.32

Question 5

If the equation for the regression line is y = 11x + 2, then a value of x = -3 will result in a predicted value for y of

Accepted Answer

A)  2 
B)  5 
C)  -31 
D)  11 
A)  2 
B)  5 
C)  -31 
D)  11

Question 6

If one found that the sum of the residuals from a regression line (with an intercept) was a large negative
value, one could conclude that there is a negative relationship between the independent and dependent
variables. 
There must have been a calculation error since the residuals sum to 0 (apart from rounding error).

Accepted Answer

A) True 
 B)False

Question 7

If the correlation coefficient is 0.93, what is the unexplained variation?

Accepted Answer

A)  7% 
B)  93% 
C)  13.5% 
D)  86.5% 
A)  7% 
B)  93% 
C)  13.5% 
D)  86.5%

Question 8

An experiment is carried out to determine the relationship between the average speed (rpm) and power (hp) of a mixer. Construct a scatter plot for the data obtained in the
$\begin{array} { l l c l } & \text { Run } & \text { Average Speed, } x & \text { Power, } ^ { y } \ & 1 & 325.0 & 1.10 \ & 2 & 348.9 & 1.40 \ & 3 & 312.9 & 1.07 \ & 4 & 230.0 & 0.25 \ \text { experiment. } & 6 & 269.2 & 0.64 \ & 5 & 305.0 & 0.93 \end{array}$

Accepted Answer

The answer of An experiment is carried out to determine...

Question 9

For a prediction value of y' from a specific value x, which of the following contribute to the prediction error?

Accepted Answer

A)  The error in estimating the slope 
B)  The error in estimating the intercept 
C)  The standard error of the estimate 
D)  All of the above 
A)  The error in estimating the slope 
B)  The error in estimating the intercept 
C)  The standard error of the estimate 
D)  All of the above

Question 10

When the x-axis and y-axis have been truncated, the y-intercept can be used to graph the regression
line.

Accepted Answer

A) True 
 B)False

Question 11

If the correlation coefficient is 0.79, what is the explained variation?

Accepted Answer

A)  37.6% 
B)  62.4% 
C)  79% 
D)  21% 
A)  37.6% 
B)  62.4% 
C)  79% 
D)  21%

Question 12

The possible relationship between pairs of data values could be examined from a

Accepted Answer

A)  Histogram 
B)  Scatter plot 
C)  Pareto graph 
D)  Pie chart 
A)  Histogram 
B)  Scatter plot 
C)  Pareto graph 
D)  Pie chart

Question 13

When r is not significantly different from 0, the best predictor of y is the mean of the __________ of
y. 
________________________________________

Accepted Answer

The answer of When r is not significantly different from...

Question 14

Compute the correlation coefficient for the data below

Accepted Answer

A)  -0.484 
B)  0.235 
C)  0.000 
D)  -0.323 
A)  -0.484 
B)  0.235 
C)  0.000 
D)  -0.323

Question 15

As a researcher collects more and more data, the 95% prediction intervals in general

Accepted Answer

A)  become narrower and narrower, with the widths getting closer and closer to 0 
B) become narrower and narrower, but the widths are always more than approximately 2 times the standard error of the estimate 
C) become narrower and narrower, but the widths are always more than approximately 4 times the standard error of the estimate 
D)  become narrower and narrower, but the widths are always more than approximately 4 times the slope 
A)  become narrower and narrower, with the widths getting closer and closer to 0 
B) become narrower and narrower, but the widths are always more than approximately 2 times the standard error of the estimate 
C) become narrower and narrower, but the widths are always more than approximately 4 times the standard error of the estimate 
D)  become narrower and narrower, but the widths are always more than approximately 4 times the slope

Question 16

In a __________ relationship, as one variable increases, the other variable decreases, and vice versa. 
________________________________________

Accepted Answer

The answer of In a __________ relationship, as one variable...

Question 17

Test the significance of the correlation coefficient $\mathrm { r }$ at $\ddagger = .05$ for the data below 
$\begin{array}{cccccc}
\mathrm{X} \text { values } & -5 & -3 & 0 & 3 & 5 \
\mathrm{Y} \text { values } & 3 & 1 & -3 & -4 & -1
\end{array}$

Accepted Answer

A)  Reject $= 0$ because $2.58 > 2.57$ 
B)  Do not reject $- = 0$ because $- 1.91  2.78$ 
D)  Do not reject $= 0$ because $- 1.91 > - 3.18$ 
A)  Reject $= 0$ because $2.58 > 2.57$ 
B)  Do not reject $- = 0$ because $- 1.91  2.78$ 
D)  Do not reject $= 0$ because $- 1.91 > - 3.18$

Question 18

In a multiple regression model $$y ^ { \prime } = - 10 + 5 x _ { 1 } + 16 x _ { 2 } + 17 x _ { 3 } + 2 x _ { 4 } \text {, if the } x _ { 1 } \text { value changes by } 2$$ then the predicted value for y will change by

Accepted Answer

A)  10 
B)  32 
C)  0 
D)  30 
A)  10 
B)  32 
C)  0 
D)  30

Question 19

$$\begin{array}{l}
\text { The western city wishes to see if there is a relationship between the summer temperature and the amount }\
\begin{array} { c c c } 
& \left. \operatorname { Temp } ^ { \circ } { } ^ { \circ } \mathrm { C } \right) & \text { Kilowatts, } { } ^ { y } \
& 22.7 & 680 \
& 25.5 & 760 \
& 29.4 & 910 \
& 36.6 & 1,510 \
& 38.8 & 1,170 \
& 27.2 & 837 \
\text { of electricity used (in kilowatts). } & 24.4 & 600 \
& 40.5 & 1,800
\end{array}
\end{array}$$
-A correlation coefficient computed for $n = 18$ and $a = 0.10$ is $r = 0.692$. Using the $t$-test for the correlation coefficient, what are the critical values?

Accepted Answer

A)  $\pm 2.120$ 
B)  $\pm 2.101$ 
C)  $\pm 1.734$ 
D)  $\pm 1.746$ 
A)  $\pm 2.120$ 
B)  $\pm 2.101$ 
C)  $\pm 1.734$ 
D)  $\pm 1.746$

Question 20

$$\text { Draw a scatter plot for the following data that show the demand for a product (in hundreds) and its price }$$ $\text { (in dollars) charged in nine different cities }$

$\begin{array}{lcl}
\text { City } & \text { Price, } x & \text { Demand, } y \
1 & 23 & 17 \
2 & 18 & 48 \
3 & 19 & 41 \
4 & 21 & 38 \
5 & 20 & 33 \
6 & 25 & 17 \
7 & 22 & 35 \
8 & 17 & 52 \
9 & 22 & 24
\end{array}$

Accepted Answer

The answer of \[\text { Draw a scatter plot for...

The standard error of estimate is the square root of the unexplained variation.

Compute the slope of the regression line for the data X values -3 -1 2 5 10 below. Y values 5 4 -2 4 -3

Compute the intercept of the regression line for the data below. values -3 0 6 values 6 5 -2

If the equation for the regression line is y = 11x + 2, then a value of x = -3 will result in a predicted value for y of

If the correlation coefficient is 0.93, what is the unexplained variation?

An experiment is carried out to determine the relationship between the average speed (rpm) and power (hp) of a mixer. Construct a scatter plot for the data obtained in the Run Average Speed, x 1 325.0 1.10 2 348.9 1.40 3 312.9 1.07 4 230.0 0.25 experiment. 6 269.2 0.64 5 305.0 0.93

For a prediction value of y' from a specific value x, which of the following contribute to the prediction error?

When the x-axis and y-axis have been truncated, the y-intercept can be used to graph the regression line.

If the correlation coefficient is 0.79, what is the explained variation?

The possible relationship between pairs of data values could be examined from a

When r is not significantly different from 0, the best predictor of y is the mean of the of y. ______________________________

Compute the correlation coefficient for the data below

As a researcher collects more and more data, the 95% prediction intervals in general

In a relationship, as one variable increases, the other variable decreases, and vice versa. ______________________________

Test the significance of the correlation coefficient $\mathrm { r }$ at $\ddagger = .05$ for the data below values -5 -3 0 3 5 values 3 1 -3 -4 -1

In a multiple regression model $y ^ { \prime } = - 10 + 5 x _ { 1 } + 16 x _ { 2 } + 17 x _ { 3 } + 2 x _ { 4 } \text {, if the } x _ { 1 } \text { value changes by } 2$ then the predicted value for y will change by

$\text { Draw a scatter plot for the following data that show the demand for a product (in hundreds) and its price }$ $\text { (in dollars) charged in nine different cities }$ City Price, x Demand, y 1 23 17 2 18 48 3 19 41 4 21 38 5 20 33 6 25 17 7 22 35 8 17 52 9 22 24

The Nature of Probability and Statistics

Frequency Distributions and Graphs

Data Description

Discrete Probability Distributions

The Normal Distribution

Confidence Intervals and Sample Size

Hypothesis Testing

Testing the Difference Between Two Means, Two Proportions, and Two Variances

Chi-Square and Analysis of Variance Anova

Tables

Data Bank

Glossary

Filters

Exam 9: Correlation and Regression

The standard error of estimate is the square root of the unexplained variation.

Compute the slope of the regression line for the data X values -3 -1 2 5 10 below. Y values 5 4 -2 4 -3

Compute the intercept of the regression line for the data below. values -3 0 6 values 6 5 -2

If the equation for the regression line is y = 11x + 2, then a value of x = -3 will result in a predicted value for y of

If the correlation coefficient is 0.93, what is the unexplained variation?

An experiment is carried out to determine the relationship between the average speed (rpm) and power (hp) of a mixer. Construct a scatter plot for the data obtained in the Run Average Speed, x 1 325.0 1.10 2 348.9 1.40 3 312.9 1.07 4 230.0 0.25 experiment. 6 269.2 0.64 5 305.0 0.93

For a prediction value of y' from a specific value x, which of the following contribute to the prediction error?

When the x-axis and y-axis have been truncated, the y-intercept can be used to graph the regression line.

If the correlation coefficient is 0.79, what is the explained variation?

The possible relationship between pairs of data values could be examined from a

When r is not significantly different from 0, the best predictor of y is the mean of the __________ of y. ________________________________________

Compute the correlation coefficient for the data below

As a researcher collects more and more data, the 95% prediction intervals in general

In a __________ relationship, as one variable increases, the other variable decreases, and vice versa. ________________________________________

Test the significance of the correlation coefficient r\mathrm { r }r at ‡=.05\ddagger = .05‡=.05 for the data below values -5 -3 0 3 5 values 3 1 -3 -4 -1

The Nature of Probability and Statistics

Frequency Distributions and Graphs

Data Description

Discrete Probability Distributions

The Normal Distribution

Confidence Intervals and Sample Size

Hypothesis Testing

Testing the Difference Between Two Means, Two Proportions, and Two Variances

Chi-Square and Analysis of Variance Anova

Tables

Data Bank

Glossary

Filters

When r is not significantly different from 0, the best predictor of y is the mean of the of y. ______________________________

In a relationship, as one variable increases, the other variable decreases, and vice versa. ______________________________

Test the significance of the correlation coefficient $\mathrm { r }$ at $\ddagger = .05$ for the data below values -5 -3 0 3 5 values 3 1 -3 -4 -1