Chapter 13
Use the following to answer questions 62-63:
For a sample of 17 values of x and y,
yy
SS =
127,
xy
SS =
–99, and b = –0.91.
62. The standard deviation of errors for the regression of y on x, rounded to three decimal
places, is:
63. The coefficient of determination for the regression of y on x, rounded to three decimal
places, is:
Use the following to answer questions 64-65:
The table shown below gives six pairs of x and y values.
x
y
16
8
20
13
12
9
10
4
9
6
9
4
64. The standard deviation of errors for the regression of y on x, rounded to three decimal
places, is:
65. The coefficient of determination for the regression of y on x, rounded to three decimal
places, is:
Chapter 13
Use the following to answer questions 66-67:
The following table lists the monthly incomes (in hundreds of dollars) and the monthly rents paid
(in hundreds of dollars) by a sample of six families.
Monthly Income
Monthly Rent
24
7.0
16
4.5
19
6.5
31
11.6
10
4.5
27
8.5
66. The standard deviation of errors for the regression of monthly rent on monthly income,
rounded to three decimal places, is:
67. The coefficient of determination for the regression of y on x, rounded to three decimal
places, is:
Use the following to answer questions 68-69:
The following table lists the ages (in years) and the prices (in thousands of dollars) by a sample
of six houses.
Age
Price
27
165
15
182
3
205
35
161
7
180
18
161
68. The standard deviation of errors for the regression of y on x, rounded to three decimal
places, is:
Chapter 13
Page 14
69. The coefficient of determination for the regression of y on x, rounded to three decimal
places, is:
70. The slope, b, of the regression line:
A) is a point estimator of the slope of the population regression line
B) possesses no sampling distribution
C) will have the same value for all samples taken from the population
D) is not affected by the elements taken from the population
71. For a data set of x and y values, the value of
xx
SS
= 266 and the standard deviation of
errors for the regression of y on x is 8.875. The standard deviation of the sampling
distribution of b, rounded to three decimal places, is:
72. For a data set of x and y values, the value of
xx
SS
= 944 and the standard deviation of
errors for the regression of y on x is 72.937. The standard deviation of the sampling
distribution of b, rounded to three decimal places, is:
73. For a data set of x and y values, the value of
xx
SS
= 66 and the standard deviation of
errors for the regression of y on x is 4.345. The standard deviation of the sampling
distribution of b, rounded to three decimal places, is:
Use the following to answer questions 74-76:
For a data set of 10 values of x and y, the value of
xx
SS
= 86, the standard deviation of errors for
the regression of y on x is 3.662, and the value of b is 3.00.
For the purpose of running a hypothesis test, the null hypothesis is that the slope of the
population regression line of y on x is zero and the alternative hypothesis is that the slope of this
population regression line is different from zero. The significance level is 5%.
Chapter 13
Page 15
74. The 95% confidence interval for the slope, B, of the population regression line is:
75. What are the critical values of t?
A) -2.306 and 2.306 C) -1.812 and 1.812
B) -2.228 and 2.228 D) -1.860 and 1.860
76. What is the value of the test statistic, t, rounded to three decimal places?
Use the following to answer questions 77-79:
For a data set of 8 values of x and y, the value of
xx
SS
= 180, the standard deviation of errors for
the regression of y on x is 9.237, and the value of b is –6.28.
For the purpose of running a hypothesis test, the null hypothesis is that the slope of the
population regression line of y on x is zero and the alternative hypothesis is that the slope of this
population regression line is less than zero. The significance level is 1%.
77. The 99% confidence interval for the slope, B, of the population regression line is:
78. What is the critical value of t?
A) -2.896 B) -2.998 C) -3.499 D) -3.143
79. What is the value of the test statistic, t, rounded to three decimal places?
Use the following to answer questions 80-82:
For a data set of 15 values of x and y, the value of
xx
SS
= 313, the standard deviation of errors
for the regression of y on x is 8.347, and the value of b is 1.78.
For the purpose of running a hypothesis test, the null hypothesis is that the slope of the
population regression line of y on x is zero and the alternative hypothesis is that the slope of this
population regression line is greater than zero. The significance level is 5%.
Chapter 13
80. The 90% confidence interval for the slope, B, of the population regression line is:
81. What is the critical value of t?
A) 1.753 B) 1.751 C) 1.771 D) 2.131
82. What is the value of the test statistic, t, rounded to three decimal places?
Use the following to answer questions 83-85:
The following table lists the monthly incomes (in hundreds of dollars) and the monthly rents paid
(in hundreds of dollars) by a sample of six families.
Monthly Income
Monthly Rent
24
7.0
16
4.5
19
6.5
31
11.6
10
4.5
27
8.5
83. The 99% confidence interval for the slope, B, of the population regression line is:
84. The null hypothesis is that the slope of the population regression line of monthly rent on
monthly income is zero and the alternative hypothesis is that the slope of this population
regression line is greater than zero. The significance level is 1%. What is the critical
value of t?
A) 3.747 B) 3.143 C) 3.365 D) 4.032
85. The null hypothesis is that the slope of the population regression line of monthly rent on
monthly income is zero and the alternative hypothesis is that the slope of this population
regression line is greater than zero. The significance level is 1%. What is the value of the
test statistic, t, rounded to three decimal places?
Chapter 13
Use the following to answer questions 86-88:
The following table lists the ages (in years) and the prices (in thousands of dollars) by a sample
of six houses.
Age
Price
27
165
15
182
3
205
35
161
7
180
18
161
86. The 95% confidence interval for the slope, B, of the population regression line of price on
age is:
87. The null hypothesis is that the slope of the population regression line of price on age is
zero and the alternative hypothesis is that the slope of this population regression line is
less than zero. The significance level is 5%. What is the critical value of t?
A) -2.015 B) -2.132 C) -1.943 D) -2.447
88. The null hypothesis is that the slope of the population regression line of price on age is
zero and the alternative hypothesis is that the slope of this population regression line is
less than zero. The significance level is 5%. What is the value of the test statistic, t,
rounded to three decimal places?
89. The value of the correlation coefficient is always:
A) in the range 0 to 1 C) in the range -1 to 1
B) less than zero D) greater than zero
Chapter 13
90. A perfect positive correlation means:
A) the points in a scatter diagram lie on an upward sloping line
B) the points in a scatter diagram lie on a downward sloping line
C) r is equal to -1
D) r is equal to 0
91. A perfect negative correlation means:
A) the points in a scatter diagram lie on an upward sloping line
B) the points in a scatter diagram lie on a downward sloping line
C) r is equal to 1
D) r is equal to 0
92. A strong positive correlation means:
A) the points in a scatter diagram lie on an upward sloping line
B) the points in a scatter diagram lie on a downward sloping line
C) r is close to 1
D) r is close to -1
93. A strong negative correlation means:
A) the points in a scatter diagram lie on an upward sloping line
B) the points in a scatter diagram lie on a downward sloping line
C) r is close to -1
D) r is close to 1
94. A weak positive correlation means:
A) the points in a scatter diagram are very close to an upward sloping line
B) the points in a scatter diagram are very close to a downward sloping line
C) r is positive and close to zero
D) r is close to 1
Chapter 13
95. A weak negative correlation means:
A) the points in a scatter diagram are very close to an upward sloping line
B) the points in a scatter diagram are very close to a downward sloping line
C) r is negative and close to zero
D) r is close to -1
96. The value of the correlation coefficient is zero if the points in a scatter diagram:
A) lie on an upward sloping line C) are scattered all over the diagram
B) lie on a downward sloping line D) are close to the regression line
97. Given that
xx
SS
= 276,
yy
SS
= 183, and
xy
SS
= 153, what is the value of the
correlation coefficient, rounded to three decimal places?
98. Given that
xx
SS
= 853,
yy
SS
= 642, and
xy
SS
= 314, what is the value of the
correlation coefficient, rounded to three decimal places?
99. Given that
xx
SS
= 241,
yy
SS
= 326, and
xy
SS
= –71, what is the value of the
correlation coefficient, rounded to three decimal places?
Chapter 13
Use the following to answer question 100:
The following table lists the monthly incomes (in hundreds of dollars) and the monthly rents paid
(in hundreds of dollars) by a sample of six families.
Monthly Income
Monthly Rent
24
7.0
16
4.5
19
6.5
31
11.6
10
4.5
27
8.5
100. What is the value of the correlation coefficient?
Use the following to answer question 101:
The following table lists the ages (in years) and the prices (in thousands of dollars) by a sample
of six houses.
Age
Price
27
165
15
182
3
205
35
161
7
180
18
161
101. What is the value of the correlation coefficient?
Chapter 13
Page 21
Use the following to answer questions 102-103:
The following table lists the monthly incomes (in hundreds of dollars) and the monthly rents paid
(in hundreds of dollars) by a sample of six families.
Monthly Income
Monthly Rent
24
7.0
16
4.5
19
6.5
31
11.6
10
4.5
27
8.5
102. What is the 99% confidence interval for the mean monthly rent of all families with a
monthly income of $2500, rounded to the nearest penny?
103. What is the 99% confidence interval for the mean monthly rent of a randomly selected
family with a monthly income of $2500, rounded to the nearest penny?
Use the following to answer questions 104-105:
The following table lists the ages (in years) and the prices (in thousands of dollars) by a sample
of six houses.
Age
Price
27
165
15
182
3
205
35
161
7
180
18
161
Chapter 13
Page 22
104. What is the 90% confidence interval for the average price of all 16-year old homes,
rounded to the nearest dollar?
105. What is the 90% confidence interval for the average price of all 16-year old homes,
rounded to the nearest dollar?