Chapter 3 test bank questions (plus printed off pages)

64. Excel's _____ function can be used to compute the sample standard deviation.

STDEV.S

97. Which of the following values of r indicates the strongest correlation?

-.9

99. If the data distribution is symmetric, the skewness is _____.

0

60. The standard deviation of a sample of 100 observations is 64. The variance of the sample is which of the following?

10

69. Which of the following is not a measure of dispersion?

50th percentile

8. The empirical rule states that, for data having a bell-shaped distribution, the portion of data values being within one standard deviation of the mean is approximately _____.

68%

59. The variance of a sample of 81 observations is 64. The standard deviation of the sample is which of the following?

8

24. Excel's _____ function can be used to compute the mean.

AVERAGE

94. Excel's _____ function can be used to compute the sample correlation coefficient.

CORREL

90. Excel's _____ function can be used to compute the sample covariance.

COVARIANCE.S

84. _____ can be used to make statements about the proportion of data values that must be within a specified number of standard deviations of the mean, regardless of the shape of the distribution.

Chebyshev's theorem

25. Excel's _____ function can be used to compute the middle value of an ordered data set.

MEDIAN

26. Excel's _____ function can be used to compute the data value occurring most frequently.

MODE.SNGL

74. Which of the following symbols represents the size of a population?

N

23. Since the mode is the most frequently occurring data value, it _____.

None of the answers are correct (below) -can never be larger than the mean -is always larger than the median -is always larger than the mean

66. The coefficient of variation is _____.

None of the answers are correct (below) -the same as the variance -the square root of the variance -the square of the standard deviation

17. The mean of the sample _____.

None of the answers are correct.(below) -is always larger than the mean of the population from which the sample was taken -is always smaller than the mean of the population from which the sample was taken -can never be zero

21. Since the median is the middle value of a data set, it must always be _____.

None of the answers are correct.(below) -smaller than the mode -larger than the mode -smaller than the mean

65. Excel's _____ function can be used to compute the population standard deviation.

STDEV.P

57. If the variance of a data set is correctly computed with the formula using n − 1 in the denominator, which of the following is true?

The data set is a sample.

85. _____ can be used to determine the percentage of data values that must be within one, two, and three standard deviations of the mean for data having a bell-shaped distribution.

The empirical rule

51. The interquartile range is used as a measure of variability to overcome what difficulty of the range?

The range is influenced too much by extreme values.

96. If r = 0.48 for data set A and r = -0.48 for data set B, which of the following is true?

The two data sets have the same level of correlation.

63. Excel's _____ function can be used to compute the population variance.

VAR.P

62. Excel's _____ function can be used to compute the sample variance.

VAR.S

77. Which of the following symbols represents the mean of a sample?

X with a line over it

9. A box plot is a graphical representation of data that is based on _____.

a five-number summary

89. Positive values of covariance indicate _____.

a positive relation between the x and y variables

55. The sum of deviations of the individual data elements from their mean is _____.

always equal to zero

56. The value of the sum of the squared deviations from the mean, i.e., must always be _____.

at least zero

28. In computing the pth percentile, if the index i is an integer the pth percentile is the _____.

average of data values in positions i and i + 1

87. A graphical summary of data that is based on a five-number summary is a _____.

box plot

93. The correlation coefficient _____.

cannot be larger than 1

6. In computing descriptive statistics for grouped data, the _____ are used to approximate the data values in each class.

class midpoints

16. The mean of a sample is _____.

computed by summing all the data values and dividing the sum by the number of items

91. A numerical measure of linear association between two variables is the _____.

correlation coefficient

52. The sample variance _____.

could be smaller, equal to, or larger than the true value of the population variance

7. Which of the following is NOT a measure of variability of a single variable?

covariance

88. A numerical measure of linear association between two variables is the _____.

covariance

106. A set of visual displays organizing and presenting information used to monitor the performance of a company or organization in a manner that is easy to read, understand, and interpret is called a _____.

data dashboard

1. The interquartile range is the difference between the _____.

first and third quartiles

102. The measure of location often used in analyzing growth rates in financial data is the _____.

geometric mean

101. When the data are positively skewed, the mean will usually be _____.

greater than the median

15. A graph with skewness -1.8 would be which of the following?

highly skewed right

18. In statistics, what does IQR mean?

inter-quartile range

68. Which of the following is a measure of dispersion?

interquartile range

20. If a data set has an even number of observations, the median _____.

is the average value of the two middle items when all items are arranged in ascending order

31. The first quartile _____.

is the same as the 25th percentile

10. The coefficient of variation indicates how large the standard deviation is relative to the _____.

mean

3. Generally, which of the following is the least appropriate measure of central tendency for a data set that contains outliers?

mean

34. The measure of location most likely to be influenced by extreme values in the data set is the _____.

mean

86. In a five-number summary, which of the following is NOT used for data summarization?

mean

103. The measure of central location most often reported for annual income and property value data is the _____.

median

19. After the data have been arranged from smallest value to largest value, the value in the middle is called the _____.

median

29. The 50th percentile is the _____.

median

27. The five-number summary consists of what five statistical measures?

min, Q1, median, Q3, max

22. The most frequently occurring value of a data set is called the _____.

mode

4. An important measure of location for categorical data is the _____.

mode

58. During a cold winter, the temperature stayed below zero for 10 days (ranging from -20 to -5). The variance of the temperatures of the 10 day period _____.

must be at least zero

75. Which of the following symbols represents the size of a sample?

n

100. For data skewed to the left, the skewness is _____.

negative

53. The variance of a sample or a population cannot be _____.

negative

61. The numerical value of the standard deviation can never be _____.

negative

71. The descriptive measure of dispersion that is based on the concept of a deviation about the mean is _____.

neither the range nor the interquartile range

83. A(n) _____ is an unusually small or unusually large data value.

outlier

72. The symbol for _____ is

population correlation

13. A numerical measure, such as a mean, computed from a population is known as a _____.

population parameter

49. The difference between the largest and smallest data values is the _____.

range

5. The measure of variability easiest to compute, but seldom used as the only measure, is the _____.

range

70. The measure of dispersion that is influenced most by extreme values is the _____.

range

54. The symbol for _____ is r.

sample correlation

12. A numerical measure computed from a sample, such as sample mean, is known as a _____.

sample statistic

98. An important numerical measure related to the shape of a distribution is the _____.

skewness

2. The variance is equal to the _____.

squared value of the standard deviation

81. The symbol σ is used to represent the _____.

standard deviation of a population

50. The interquartile range is _____.

the difference between the third and first quartiles

30. The 75th percentile is also the _____.

third quartile

11. Which of the following descriptive statistics is NOT measured in the same units as the data?

variance

32. Which of the following is NOT a measure of location?

variance

33. The median of a sample will always equal the _____.

variance

73. The descriptive measure NOT measured in the same units as the original data is the _____.

variance

79. The symbol σ 2 is used to represent the _____.

variance of a population

95. A mean computed in such a way that each data value is given a weight reflecting its importance is referred to as a(n) _____.

weighted mean

82. The _____ denotes the number of standard deviations xi is from the mean .

z-score

76. Which of the following symbols represents the mean of a population?

μ

80. Which of the following symbols represents the standard deviation of a population?

σ

78. Which of the following symbols represents the variance of a population?

σ 2

92. The correlation coefficient ranges from which two values?

−1 and +1