Question 1

The following data are the heights (in cm) of the 25 students in a business statistics class: $$\begin{array} { | l | l | l | l | l | l | l | l | l | l | } 
\hline 164 & 148 & 137 & 157 & 173 & 156 & 177 & 172 & 169 & 165 \
\hline 145 & 168 & 163 & 162 & 174 & 152 & 156 & 168 & 154 & 151 \
\hline 174 & 146 & 134 & 140 & 171 & & & & & \
\hline
\end{array}$$ a. Compute the range of the data.
b. Compute the range approximation to the standard deviation of the data. (Hint: S $\approx$ Range/4.)

Accepted Answer

The answer of The following data are the heights (in...

Question 2

The following data represent the salaries (in thousands of dollars) of a sample of 13 employees of a firm: $$\begin{array} { | l | l | l | l | l | l | l | } 
\hline 26.5 & 23.5 & 29.7 & 24.8 & 21.1 & 24.3 & 20.4 \
\hline 22.7 & 27.2 & 23.7 & 24.1 & 24.8 & 28.2 & \
\hline
\end{array}$$ Compute the range.

Accepted Answer

The answer of The following data represent the salaries (in...

Question 3

The following data represent the weights (in kilograms) of a sample of 30 horses:
Weight
165
175
150
155
173
149
145
153
153
153
152
145
164
143
170
175
148
174
171
156
166
168
152
150
173
168
146
155
172
159
Compute the sample mean weight.

Accepted Answer

The answer of The following data represent the weights (in...

Question 4

When the distribution is skewed, the interquartile range is a better measure of variability than the standard deviation.

Accepted Answer

A) True 
 B)False

Question 5

A basketball player has the following points for seven games: 20, 25, 32, 18, 19, 22, 30. Compute the following measures of central location and variability:
a. mean.
b. median.
c. standard deviation.
d. coefficient of variation.

Accepted Answer

The answer of A basketball player has the following points...

Question 6

A sample of eight observations of variables x and y is shown below: $$\begin{array} { | l | r | r | r | r | r | r | r | r | } 
\hline x & 5 & 3 & 7 & 9 & 2 & 4 & 6 & 8 \
\hline y & 20 & 23 & 15 & 11 & 27 & 21 & 17 & 14 \
\hline
\end{array}$$ Draw the scatter diagram and plot the least-squares line.

Accepted Answer

The answer of A sample of eight observations of variables...

Question 7

In a symmetric distribution, the mean is the most used measure of central location for quantitative data.

Accepted Answer

A) True 
 B)False

Question 8

The following data represent the weights (in kilograms) of a sample of 30 horses:
Weight
165
175
150
155
173
149
145
153
153
153
152
145
164
143
170
175
148
174
171
156
166
168
152
150
173
168
146
155
172
159
Construct a box plot for the weights.

Accepted Answer

The answer of The following data represent the weights (in...

Question 9

The following data are the heights (in cm) of the 25 students in a business statistics class: $$\begin{array} { | l | l | l | l | l | l | l | l | l | l | } 
\hline 164 & 148 & 137 & 157 & 173 & 156 & 177 & 172 & 169 & 165 \
\hline 145 & 168 & 163 & 162 & 174 & 152 & 156 & 168 & 154 & 151 \
\hline 174 & 146 & 134 & 140 & 171 & & & & & \
\hline
\end{array}$$ a. Compute the sample mean height.
b. Compute the sample variance.
c. Compute the sample standard deviation.

Accepted Answer

The answer of The following data are the heights (in...

Question 10

Which of the following may be answered by knowing the shape of the distribution?

Accepted Answer

A)  What is the best measure of central location to use. 
B)  What is the best measure of variability to use. 
C)  What the best measure of central location and variability to use. 
D)  None of these choices are correct.

Question 11

The frequency histogram for the heights (in cm) of the 25 students in a business statistics class is given below.  What is the best measure of central location?

Accepted Answer

The answer of The frequency histogram for the heights (in...

Question 12

When a distribution is symmetric, the mean, median and the mode are all equal.

Accepted Answer

A) True 
 B)False

Question 13

The following data represent the weights (in kilograms) of a sample of 30 horses:
Weight
165
175
150
155
173
149
145
153
153
153
152
145
164
143
170
175
148
174
171
156
166
168
152
150
173
168
146
155
172
159
Compute the range and interquartile range of the data.

Accepted Answer

The answer of The following data represent the weights (in...

Question 14

Data were obtained for the weight in grams, of a sample of 10 packets of sweetener, as found in cafés. $$\begin{array} { | l | l | l | l | l | l | l | l | l | l | } 
\hline 4.5 & 5 & 5.9 & 5.4 & 5.5 & 4.7 & 4.9 & 4.7 & 4.7 & 4.6 \
\hline
\end{array}$$ Find the variance.

Accepted Answer

The answer of Data were obtained for the weight in...

Question 15

Chebyshev's theorem applies only to data sets that have a mound-shaped distribution.

Accepted Answer

A) True 
 B)False

Question 16

The following data represent the salaries (in thousands of dollars) of a sample of 13 employees of a firm: $$\begin{array} { | l | l | l | l | l | l | l | } 
\hline 26.5 & 23.5 & 29.7 & 24.8 & 21.1 & 24.3 & 20.4 \
\hline 22.7 & 27.2 & 23.7 & 24.1 & 24.8 & 28.2 & \
\hline
\end{array}$$ Compute the coefficient of variation.

Accepted Answer

The answer of The following data represent the salaries (in...

Question 17

The following data represent the salaries (in thousands of dollars) of a sample of 13 employees of a firm: $$\begin{array} { | l | l | l | l | l | l | l | } 
\hline 26.5 & 23.5 & 29.7 & 24.8 & 21.1 & 24.3 & 20.4 \
\hline 22.7 & 27.2 & 23.7 & 24.1 & 24.8 & 28.2 & \
\hline
\end{array}$$ Compute the upper quartile.

Accepted Answer

The answer of The following data represent the salaries (in...

Question 18

A media article claimed that there was a correlation between the colour of a car and the likelihood of a car being in an accident. What is wrong with this statement?

Accepted Answer

The answer of A media article claimed that there was...

Question 19

The coefficient of determination may range in values between negative one and positive one.

Accepted Answer

A) True 
 B)False

Question 20

How is the value of the correlation coefficient r affected in each of the following cases?
a. Each x value is multiplied by 4.
b. Each x value is switched with the corresponding y value.
c. Each x value is increased by 2.

Accepted Answer

The answer of How is the value of the correlation...

Exam 5: Numerical Descriptive Measures

The following data represent the salaries (in thousands of dollars) of a sample of 13 employees of a firm: $\begin{array} { | l | l | l | l | l | l | l | } \hline 26.5 & 23.5 & 29.7 & 24.8 & 21.1 & 24.3 & 20.4 \\\hline 22.7 & 27.2 & 23.7 & 24.1 & 24.8 & 28.2 & \\\hline\end{array}$ Compute the range.

The following data represent the weights (in kilograms) of a sample of 30 horses: Weight 165 175 150 155 173 149 145 153 153 153 152 145 164 143 170 175 148 174 171 156 166 168 152 150 173 168 146 155 172 159 Compute the sample mean weight.

When the distribution is skewed, the interquartile range is a better measure of variability than the standard deviation.

A basketball player has the following points for seven games: 20, 25, 32, 18, 19, 22, 30. Compute the following measures of central location and variability: a. mean. b. median. c. standard deviation. d. coefficient of variation.

A sample of eight observations of variables x and y is shown below: $\begin{array} { | l | r | r | r | r | r | r | r | r | } \hline x & 5 & 3 & 7 & 9 & 2 & 4 & 6 & 8 \\\hline y & 20 & 23 & 15 & 11 & 27 & 21 & 17 & 14 \\\hline\end{array}$ Draw the scatter diagram and plot the least-squares line.

In a symmetric distribution, the mean is the most used measure of central location for quantitative data.

The following data represent the weights (in kilograms) of a sample of 30 horses: Weight 165 175 150 155 173 149 145 153 153 153 152 145 164 143 170 175 148 174 171 156 166 168 152 150 173 168 146 155 172 159 Construct a box plot for the weights.

Which of the following may be answered by knowing the shape of the distribution?

The frequency histogram for the heights (in cm) of the 25 students in a business statistics class is given below. What is the best measure of central location?

When a distribution is symmetric, the mean, median and the mode are all equal.

The following data represent the weights (in kilograms) of a sample of 30 horses: Weight 165 175 150 155 173 149 145 153 153 153 152 145 164 143 170 175 148 174 171 156 166 168 152 150 173 168 146 155 172 159 Compute the range and interquartile range of the data.

Data were obtained for the weight in grams, of a sample of 10 packets of sweetener, as found in cafés. $\begin{array} { | l | l | l | l | l | l | l | l | l | l | } \hline 4.5 & 5 & 5.9 & 5.4 & 5.5 & 4.7 & 4.9 & 4.7 & 4.7 & 4.6 \\\hline\end{array}$ Find the variance.

Chebyshev's theorem applies only to data sets that have a mound-shaped distribution.

A media article claimed that there was a correlation between the colour of a car and the likelihood of a car being in an accident. What is wrong with this statement?

The coefficient of determination may range in values between negative one and positive one.

How is the value of the correlation coefficient r affected in each of the following cases? a. Each x value is multiplied by 4. b. Each x value is switched with the corresponding y value. c. Each x value is increased by 2.