Descriptive Statistics

Question 1

Bins (numerical data); classes (categorical data)

Answer 1

The nonoverlapping groupings of data used to create a frequency distribution

Question 2

Box plot

Answer 2

A graphical summary of data based on the quartiles of a distribution.

Question 3

Categorical data

Answer 3

Data for which categories of like items are identified by labels or names. Arithmetic operations cannot be performed on this kind of data

Question 4

Coefficient of variation

Answer 4

A measure of relative variability computed by dividing the standard deviation by the mean and multiplying by 100.

Question 5

Correlation coefficient

Answer 5

A standardized measure of linear association between two variables that takes on values between —1 and + 1. Values near —1 indicate a strong negative linear relationship, values near +1 indicate a strong positive linear relationship, and values near zero indicate the lack of a linear relationship.

Question 6

Covariance

Answer 6

A measure of linear association between two variables. Positive values indicate a positive relationship; negative values indicate a negative relationship.

Question 7

Cross-sectional data

Answer 7

Data collected at the same or approximately the same point in time.

Question 8

cumulative frequency distribution

Answer 8

A tabular summary of quantitative data showing the number of data values that are less than or equal to the upper class limit of each bin.

Question 9

Data

Answer 9

The facts and figures collected, analyzed, and summarized for presentation and interpretation.

Question 10

Empirical Rule (68-95-99.7)

Answer 10

A rule that can be used to compute the percentage of data values that must be within 1, 2, or 3 standard deviations of the mean for data that exhibit a bell-shaped distribution.

Question 11

Frequency distribution

Answer 11

A tabular summary of data showing the number of data values in each of several nonoverlapping bins.

Question 12

Geometric mean

Answer 12

A measure of central tendency that is calculated by finding the nth root of the product of n values.

Question 13

Growth factor

Answer 13

The percentage increase of a value over a period of time is calculated using the formula (1 - bake). A value less than 1 indicates negative growth, whereas a value greater than 1 indicates positive growth. The value cannot be less than zero.

Question 14

Histogram

Answer 14

A graphical presentation of a frequency distribution, relative frequency distribution, or percent frequency distribution of quantitative data constructed by placing the bin intervals on the horizontal axis and the frequencies, relative frequencies, or percent frequencies on the vertical axis.

Question 15

Interquartile Range (IQR)

Answer 15

The difference between the third and first quartiles.

Question 16

mean (arithmetic mean)

Answer 16

A measure of central tendency computed by summing the data values and dividing by the number of observations.

Question 17

Median

Answer 17

A measure of central tendency provided by the value in the middle when the data are arranged in ascending order.

Question 18

Mode

Answer 18

A measure of central tendency, defined as the value that occurs with greatest frequency.

Question 19

Observation

Answer 19

A set of values corresponding to a set of variables.

Question 20

Outlier

Answer 20

An unusually large or unusually small data value.

Question 21

percent frequency distribution

Answer 21

A tabular summary of data showing the percentage of data values in each of several nonoverlapping bins.

Question 22

Percentile

Answer 22

A value such that approximately p percent of the observations have values less than the pth percentile; hence, approximately (100 - p) percent of the observations have values greater than the pth percentile. The 50th percentile is the median.

Question 23

Population

Answer 23

The set of all elements of interest in a particular study.

Question 24

Quantitative data

Answer 24

Data for which numerical values are used to indicate magnitude, such as how many or how much. Arithmetic operations such as addition, subtraction, and multiplication can be performed on this data.

Question 25

Quartile

Answer 25

The 25th, 50th, and 75th percentiles, referred to as the first quartile, second quartile (median), and third quartile, respectively. These can be used to divide a data set into four parts, with each part containing approximately 25% of the data.

Question 26

Random sampling

Answer 26

Collecting a sample that ensures that: (1) each element selected comes from the same population and (2) each element is selected independently.

Question 27

Random variable

Answer 27

A quantity whose values are not known with certainty.

Question 28

Range

Answer 28

A measure of variability, defined to be the largest value minus the smallest value.

Question 29

Relative frequency distribution

Answer 29

A tabular summary of data showing the fraction or proportion of data values in each of several nonoverlapping bins.

Question 30

Sample

Answer 30

A subset of the population.

Question 31

Scatter chart

Answer 31

A graphical presentation of the relationship between two quantitative variables. One variable is shown on the horizontal axis and the other on the vertical axis.

Question 32

Skewness

Answer 32

A measure of the lack of symmetry in a distribution.

Question 33

Standard deviation

Answer 33

A measure of variability computed by taking the positive square root of the variance.

Question 34

Time series data

Answer 34

Data that are collected over a period of time

Question 35

Variable

Answer 35

A characteristic or quantity of interest that can take on different values.

Question 36

Variation

Answer 36

Differences in values of a variable over observations.

Question 37

z-score

Answer 37

A value computed by dividing the deviation about the mean (x1 - x) by the standard deviation σ. It is referred to as a standardized value and denotes the number of standard deviations that x is from the mean.