74 Numerical Descriptive Measures
CHAPTER 3: NUMERICAL DESCRIPTIVE MEASURES
1. Which of the following statistics is not a measure of central tendency?
a) Arithmetic mean. b) Median. c) Mode. d) Q3.
ANSWER: d
TYPE: MC DIFFICULTY: Easy
KEYWORDS: measure of central tendency, arithmetic mean, median, mode, quartiles
2. Which measure of central tendency can be used for both numerical and categorical variables?
a) Arithmetic mean. b) Median. c) Mode.
d) Standard deviation.
ANSWER: c
TYPE: MC DIFFICULTY: Moderate
KEYWORDS: measure of central tendency, mode, arithmetic mean, median
3. Which of the arithmetic mean, median, and mode are resistant measures of central tendency?
a) The arithmetic mean and median only. b) The median and mode only.
c) The mode and arithmetic mean only. d) All the three are resistant measures.
ANSWER: b
TYPE: MC DIFFICULTY: Moderate
KEYWORDS: measure of central tendency, resistant to outliers, mean, median, mode
4. In a right-skewed distribution
a) the median equals the arithmetic mean. b) the median is less than the arithmetic mean. c) the median is larger than the arithmetic mean. d) none of the above.
ANSWER: b
TYPE: MC DIFFICULTY: Easy KEYWORDS: shape
Copyright ? 2010 Pearson Education, Inc. Publishing as Prentice Hall
Numerical Descriptive Measures 75
5. Which of the following statements about the median is not true?
a) It is more affected by extreme values than the arithmetic mean. b) It is a measure of central tendency. c) It is equal to Q2.
d) It is equal to the mode in bell-shaped \
ANSWER: a
TYPE: MC DIFFICULTY: Easy
KEYWORDS: median, measure of central tendency, resistant to outliers, quartile
6. In a perfectly symmetrical bell-shaped \
a) the arithmetic mean equals the median. b) the median equals the mode.
c) the arithmetic mean equals the mode. d) All the above.
ANSWER: d
TYPE: MC DIFFICULTY: Easy
KEYWORDS: shape, normal distribution
7. In a perfectly symmetrical distribution
a) the range equals the interquartile range.
b) the interquartile range equals the arithmetic mean. c) the median equals the arithmetic mean. d) the variance equals the standard deviation.
ANSWER: c
TYPE: MC DIFFICULTY: Easy KEYWORDS: shape
8. When extreme values are present in a set of data, which of the following descriptive summary
measures are most appropriate:
a) CV and range.
b) arithmetic mean and standard deviation. c) interquartile range and median. d) variance and interquartile range.
ANSWER: c
TYPE: MC DIFFICULTY: Easy
KEYWORDS: resistant to outliers, coefficient of variation, range, arithmetic mean, standard deviation, interquartile range, median, variance
Copyright ? 2010 Pearson Education, Inc. Publishing as Prentice Hall
76 Numerical Descriptive Measures
9. In general, which of the following descriptive summary measures cannot be easily approximated
from a boxplot?
a) The variance. b) The range.
c) The interquartile range. d) The median.
ANSWER: a
TYPE: MC DIFFICULTY: Easy
KEYWORDS: boxplot, variance, range, interquartile range, median
10. The smaller the spread of scores around the arithmetic mean,
a) the smaller the interquartile range. b) the smaller the standard deviation. c) the smaller the coefficient of variation. d) All the above.
ANSWER: d
TYPE: MC DIFFICULTY: Moderate
KEYWORDS: variation, arithmetic mean, interquartile range, standard deviation, coefficient of variation
11. Which descriptive summary measures are considered to be resistant statistics?
a) The arithmetic mean and standard deviation. b) The interquartile range and range. c) The mode and variance.
d) The median and interquartile range.
ANSWER: d
TYPE: MC DIFFICULTY: Moderate
KEYWORDS: resistant to outliers, arithmetic mean, standard deviation, interquartile range, range, mode, variance, median
12. In right-skewed distributions, which of the following is the correct statement?
a) The distance from Q1 to Q2 is larger than the distance from Q2 to Q3. b) The distance from Q1 to Q2 is smaller than the distance from Q2 to Q3. c) The arithmetic mean is smaller than the median. d) The mode is larger than the arithmetic mean.
ANSWER: b
TYPE: MC DIFFICULTY: Easy
KEYWORDS: shape, quartiles, arithmetic mean, mode
Copyright ? 2010 Pearson Education, Inc. Publishing as Prentice Hall
Numerical Descriptive Measures 77
13. In perfectly symmetrical distributions, which of the following is NOT a correct statement?
a) The distance from Q1 to Q2 equals to the distance from Q2 to Q3.
b) The distance from the smallest observation to Q1 is the same as the distance from Q3 to
the largest observation.
c) The distance from the smallest observation to Q2 is the same as the distance from Q2 to
the largest observation.
d) The distance from Q1 to Q3 is half of the distance from the smallest to the largest
observation.
ANSWER: d
TYPE: MC DIFFICULTY: Easy
KEYWORDS: shape, quartiles, five-number summary, quartiles
14. In left-skewed distributions, which of the following is the correct statement?
a) The distance from Q1 to Q2 is smaller than the distance from Q2 to Q3.
b) The distance from the smallest observation to Q1 is larger than the distance from Q3 to
the largest observation.
c) The distance from the smallest observation to Q2 is smaller than the distance from Q2 to
the largest observation.
d) The distance from Q1 to Q3 is twice the distance from the Q1 to Q2.
ANSWER: b
TYPE: MC DIFFICULTY: Easy
KEYWORDS: shape, quartiles, five-number summary, quartiles
15. According to the empirical rule, if the data form a \
percent of the observations will be contained within 2 standard deviations around the arithmetic mean.
a) 68.26 b) 88.89 c) 93.75 d) 95.44
ANSWER: d
TYPE: MC DIFFICULTY: Moderate
KEYWORDS: empirical rule, normal distribution
16. According to the empirical rule, if the data form a \
percent of the observations will be contained within 1 standard deviation around the arithmetic mean.
a) 68.26 b) 75.00 c) 88.89 d) 93.75
ANSWER:
Copyright ? 2010 Pearson Education, Inc. Publishing as Prentice Hall
78 Numerical Descriptive Measures
a
TYPE: MC DIFFICULTY: Moderate
KEYWORDS: empirical rule, normal distribution
17. According to the empirical rule, if the data form a \
percent of the observations will be contained within 3 standard deviations around the arithmetic mean.
a) 68.26 b) 75.00 c) 95.0 d) 99.7
ANSWER: d
TYPE: MC DIFFICULTY: Moderate
KEYWORDS: empirical rule, normal distribution
18. Which of the following is NOT a measure of central tendency?
a) The arithmetic mean. b) The median. c) The mode.
d) The interquartile range.
ANSWER: d
TYPE: MC DIFFICULTY: Easy
KEYWORDS: measure of central tendency, arithmetic mean, median, mode, interquartile range
19. Which of the following is NOT sensitive to extreme values?
a) The range.
b) The standard deviation. c) The interquartile range. d) The coefficient of variation.
ANSWER: c
TYPE: MC DIFFICULTY: Moderate
KEYWORDS: resistant to outliers, range, standard deviation, interquartile range, coefficient of variation
20. Which of the following is sensitive to extreme values?
a) The median.
b) The interquartile range. c) The arithmetic mean. d) The 1st quartile.
ANSWER: c
TYPE: MC DIFFICULTY: Moderate
KEYWORDS: resistant to outliers, median, interquartile range, arithmetic mean, quartiles
Copyright ? 2010 Pearson Education, Inc. Publishing as Prentice Hall