Question 1

The coefficient of variation gives an indication of the magnitude of the standard deviation relative to the mean.

Accepted Answer

A) True 
 B)False  True

Question 2

There are no measures of variability for nominal data.

Accepted Answer

A) True 
 B)False  True

Question 3

The width of the box in a boxplot is the mean of the data set.

Accepted Answer

A) True 
 B)False  False

Question 4

The coefficient of correlation is the covariance divided by the standard deviation

Accepted Answer

A) True 
 B)False

Question 5

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 standard deviation.

Accepted Answer

Standard d

Question 6

The coefficient of correlation is the same value as the coefficient of determination.

Accepted Answer

A) True 
 B)False

Question 7

The interquartile range is found by taking the difference between the 1st and 3rd quartiles and dividing that value by 2.

Accepted Answer

A) True 
 B)False

Question 8

Which of the following must is necessary when approximating descriptive measures for grouped data?

Accepted Answer

A)  The observations in a class are positively skewed. 
B)  The observations in a class are fairly symmetrical about the midpoint. 
C)  The observations in a class are negatively skewed. 
D)  None of these choices are correct. 
A)  The observations in a class are positively skewed. 
B)  The observations in a class are fairly symmetrical about the midpoint. 
C)  The observations in a class are negatively skewed. 
D)  None of these choices are correct.

Question 9

Which of the following statements is true for the following data values: 7, 5, 6, 4, 7, 8 and 12?

Accepted Answer

A)  The mean, median and mode are all equal. 
B) Only the mean and median are equal. 
C) Only the mean and mode are equal. 
D) Only the median and mode are equal. 
A)  The mean, median and mode are all equal. 
B) Only the mean and median are equal. 
C) Only the mean and mode are equal. 
D) Only the median and mode are equal.

Question 10

The boxplot may be used for ordinal data or numerical data.

Accepted Answer

A) True 
 B)False

Question 11

The standard deviation is expressed in terms of the original units of measurement, but the variance is not.

Accepted Answer

A) True 
 B)False

Question 12

In a bell-shaped distribution, there is no difference in the values of the mean, median and mode.

Accepted Answer

A) True 
 B)False

Question 13

Which of the following best describes the scenario when two data sets have the same range?

Accepted Answer

A)  The distances from the smallest to the largest observations in both data sets will be the same. 
B)  The smallest and largest observations are the same in both data sets. 
C)  B oth data sets will have the same mean. 
D)  B oth data sets will have the same interquartile range. 
A)  The distances from the smallest to the largest observations in both data sets will be the same. 
B)  The smallest and largest observations are the same in both data sets. 
C)  B oth data sets will have the same mean. 
D)  B oth data sets will have the same interquartile range.

Question 14

The range is considered the weakest measure of variability.

Accepted Answer

A) True 
 B)False

Question 15

Which of the following statements describes when the median is a better measure of centre than the mean?

Accepted Answer

A)  When the distribution is symmetric. 
B)  When the distribution is positively skewed. 
C)  When the distribution Is negatively skewed. 
D)  When the distribution is positively skewed or negatively skewed. 
A)  When the distribution is symmetric. 
B)  When the distribution is positively skewed. 
C)  When the distribution Is negatively skewed. 
D)  When the distribution is positively skewed or negatively skewed.

Question 16

Which of the following statements is true?

Accepted Answer

A) When approximating the sample mean for grouped data we assume that the midpoint of each class closely approximates the mean of observati ons in the class. 
B) When approximating the sample mean for grouped data we cannot assume that the midpoint of each class dosely approximates the mean of observations in the class. 
C)  Descriptive measures for grouped data are not possible.
D )None of these choices are correct. 
A) When approximating the sample mean for grouped data we assume that the midpoint of each class closely approximates the mean of observati ons in the class. 
B) When approximating the sample mean for grouped data we cannot assume that the midpoint of each class dosely approximates the mean of observations in the class. 
C)  Descriptive measures for grouped data are not possible.
D )None of these choices are correct.

Question 17

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
Determine the location and value of the upper quartile of the weights.

Accepted Answer

L₇₅= 23.25,

Question 18

The coefficient of determination lies between 0 and 1.

Accepted Answer

A) True 
 B)False

Question 19

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 variability?

Accepted Answer

The interquartile range is the

Question 20

The following data represent the ages (in years) of a sample of 25 employees from a government
department: $$\begin{array} { | l | l | l | l | l | l | l | l | l | l | } 
\hline 31 & 43 & 56 & 23 & 49 & 42 & 33 & 61 & 44 & 28 \
\hline 48 & 38 & 44 & 35 & 40 & 64 & 52 & 42 & 47 & 39 \
\hline 53 & 27 & 36 & 35 & 20 & & & & & \
\hline
\end{array}$$ Find the 60th percentile of the ages.

Accepted Answer

L₆₀ = 15.6. 60th perce

Exam 5: Numerical Descriptive Measures

The coefficient of variation gives an indication of the magnitude of the standard deviation relative to the mean.

There are no measures of variability for nominal data.

The width of the box in a boxplot is the mean of the data set.

The coefficient of correlation is the covariance divided by the standard deviation

Data were obtained for the weight in grams, of a sample of 10 packets of sweetener, as found in cafés. 4.5 5 5.9 5.4 5.5 4.7 4.9 4.7 4.7 4.6 Find the standard deviation.

The coefficient of correlation is the same value as the coefficient of determination.

The interquartile range is found by taking the difference between the 1st and 3rd quartiles and dividing that value by 2.

Which of the following must is necessary when approximating descriptive measures for grouped data?

Which of the following statements is true for the following data values: 7, 5, 6, 4, 7, 8 and 12?

The boxplot may be used for ordinal data or numerical data.

The standard deviation is expressed in terms of the original units of measurement, but the variance is not.

In a bell-shaped distribution, there is no difference in the values of the mean, median and mode.

Which of the following best describes the scenario when two data sets have the same range?

The range is considered the weakest measure of variability.

Which of the following statements describes when the median is a better measure of centre than the mean?

Which of the following statements is true?

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 Determine the location and value of the upper quartile of the weights.

The coefficient of determination lies between 0 and 1.

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 variability?

The following data represent the ages (in years) of a sample of 25 employees from a government department: 31 43 56 23 49 42 33 61 44 28 48 38 44 35 40 64 52 42 47 39 53 27 36 35 20 Find the 60th percentile of the ages.

What Is Statistics

Types of Data, Data Collection and Sampling

Graphical Descriptive Methods Nominal Data

Graphical Descriptive Techniques Numerical Data

Probability

Random Variables and Discrete Probability Distributions

Continuous Probability Distributions

Statistical Inference: Introduction

Sampling Distributions

Estimation: Describing a Single Population

Estimation: Comparing Two Populations

Hypothesis Testing: Describing a Single Population

Hypothesis Testing: Comparing Two Populations

Inference About Population Variances

Analysis of Variance

Additional Tests for Nominal Data: Chi-Squared Tests

Simple Linear Regression and Correlation

Multiple Regression

Model Building

Nonparametric Techniques

Statistical Inference: Conclusion

Time-Series Analysis and Forecasting

Index Numbers

Decision Analysis

Filters