Chapter 3

Question 1

Statistical measures used to yield information about the center or middle part of a
group of numbers are called _______________.

Answer 1

Measures of Central Tendency

Question 2

. The “average” is the _______________.

Answer 2

Mean

Question 3

The value occurring most often in a group of numbers is called _______________.

Answer 3

Mode

Question 4

In a set of 110 numbers arranged in order, the median is located at the
_______________ position.

Answer 4

Mode

Question 5

If a set of data has an odd number of values arranged in ascending order, the median
is the ________________ value.

Answer 5

Middle

Question 6

Consider the data: 5, 4, 6, 6, 4, 5, 3, 2, 6, 4, 6, 3, 5
Answer questions 6-8 using this data.

The mode is _______________.

Answer 6

6

Question 7

Consider the data: 5, 4, 6, 6, 4, 5, 3, 2, 6, 4, 6, 3, 5
Answer questions 6-8 using this data.

The median is _______________.

Answer 7

5

Question 8

Consider the data: 5, 4, 6, 6, 4, 5, 3, 2, 6, 4, 6, 3, 5
Answer questions 6-8 using this data.

The mean is _______________.

Answer 8

4.54

Question 9

If a set of values is a population, then the mean is denoted by _______________.

Answer 9

Mu

Question 10

Measures of variability describe the _______________ of a set of data.

Answer 10

Spread or Dispersion

Question 11

Use the following population data for Questions 11-14:

	27  65  28  61  34  91  61  37  58  31
	43  47  44  20  48  50  49  43  19  52 The range of the data is \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.

Answer 11

72

Question 12

Use the following population data for Questions 11-14:

	27  65  28  61  34  91  61  37  58  31
	43  47  44  20  48  50  49  43  19  52 .    The value of Q1 is \_\_\_\_\_\_\_\_\_\_\_\_\_, Q2 is \_\_\_\_\_\_\_\_\_\_\_\_, and Q3 is \_\_\_\_\_\_\_\_\_\_\_\_.

Answer 12

Q1 = 32.5, Q2 = 45.5, Q3 = 55

Question 13

Use the following population data for Questions 11-14:

	27  65  28  61  34  91  61  37  58  31
	43  47  44  20  48  50  49  43  19  52 The interquartile range is \_\_\_\_\_\_\_\_\_\_\_\_\_.

Answer 13

IQR = 22.5

Question 14

Use the following population data for Questions 11-14:

	27  65  28  61  34  91  61  37  58  31
	43  47  44  20  48  50  49  43  19  52 The value of the 34th percentile is \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.

Answer 14

P34 = 37

Question 15

Subtracting each value of a set of data from the mean produces _______________
from the mean.

Answer 15

Deviations

Question 16

The sum of the deviations from the mean is always _______________.

Answer 16

Zero

Question 17

The variance is the _______________ of the standard deviation.

Answer 17

Square

Question 18

The population variance is computed by using _______________ in the
denominator. Whereas, the sample variance is computed by using
_______________ in the denominator.

Answer 18

N, n – 1

Question 19

If the sample standard deviation is 9, then the sample variance is
_______________.

Answer 19

81

Question 20

Consider the data below and answer questions 20-21 using the data:

			2, 3, 6, 12

The sample variance for this data is _______________.

Answer 20

20.25

Question 21

Consider the data below and answer questions 20-21 using the data:

			2, 3, 6, 12

The population standard deviation for this data is _______________.

Answer 21

3.897

Question 22

In estimating what proportion of values fall within so many standard deviations of the mean, an analyst should use if the shape of the distribution of numbers is unknown

Answer 22

Chebyshev’s Theorem

Question 23

Suppose a distribution of numbers is mound shaped with a mean of 150 and a variance of 225. Approximately _______________ percent of the values fall between 120 and 180. Between _______________ and _______________ fall
99.7% of these values.

Answer 23

95, 105, and 195

Question 24

The shape of a distribution of numbers is unknown. The distribution has a mean of 275 and a standard deviation of 12. The value of k for 299 is _______________. At least _______________ percent of the values fall between 251 and 299

Answer 24

2, 75

Question 25

Suppose data are normally distributed with a mean of 36 and a standard deviation of 4.8. The z score for 30 is _______________. The z score for 40 is _______________.

Answer 25

–1.25, 0.83

Question 26

A normal distribution of values has a mean of 74 and a standard deviation of 21.
The coefficient of variation for this distribution is _______________?

Answer 26

28.38%

Question 27

If a unimodal distribution has a mean of 50, a median of 48, and a mode of 47, the distribution is skewed _______________.

Answer 27

Right or Positively skewed

Mean > Median > Mode

Question 28

In a box plot, the inner fences are computed by ___________________ and ____________________. The outer fences are computed
___________________ and ___________________.

Answer 28

Q1 - 1.5 IQR and Q3 + 1.5 IQR

Q1 - 3.0 IQR and Q3 + 3.0 IQR

Question 29

Data values that lie outside the mainstream of values in a distribution are referred to
as __________________.

Answer 29

Outliers