Chapter 15

Question 1

Statistic

Answer 1

A numerical quantity that describes a sample

Question 2

Parameter

Answer 2

A numerical quantity that describes a population

Question 3

Descriptive statistics

Answer 3

The type of statistical analysis focused on describing, summarizing, or explaining a set of data

Question 4

Graphical representations

Answer 4

Differentiate among the types of graphic representations of data and when they should be used

• Bar graph
• Histogram
• Line graph
• Scatterplot

Question 5

Central tendency

Answer 5

Numerical value expressing what is typical of the values of a quantitative variable

Question 6

Variability

Answer 6

Numerical value expressing how spread out or how much variation is present in the values of a quantitative variable

Question 7

Relationships among variables

Answer 7

Determining whether independent and dependent variables are related
- They use independent (or predictor) variables to “explain variance” in dependent (or outcome) variables

Question 8

Bar graphs

Answer 8

Graph that uses vertical bars to represent the data values of a categorical variable
- Display frequencies for a categorical variable

Question 9

Histogram

Answer 9

Graph depicting frequencies and distribution of a quantitative variable
- Display frequencies across a variable that is quantitative

Question 10

Line graph

Answer 10

A graph relying on the drawing of one or more lines connecting data points
- Highlights comparisons across one or more variables

Question 11

Scatterplot

Answer 11

A graphical depiction of the relationship between two quantitative variables

Question 12

Frequency distribution

Answer 12

Data arrangement in which the frequencies of each unique data value is shown

Question 13

Mode

Answer 13

The most frequently occurring number

Question 14

Median

Answer 14

The center point in an ordered set of numbers

Question 15

Mean

Answer 15

The arithmetic average

Question 16

Range

Answer 16

The highest number minus the lowest number

Question 17

Variance

Answer 17

The average deviation of data values from their mean in squared units
- An index of how all values differ or diverge from the average score (mean)

Question 18

Standard deviation

Answer 18

The square root of the variance

- Used as a comparison to evaluate how each score for the variables differ from the mean

Question 19

Normal distribution

Answer 19

A theoretical distribution that follows the 68, 95, 99.7 percent rule
- Interprets scores in terms of how far they are from the mean using a normalized standard
- 68, 95, 99.7 percent rule: rule stating percentage of
cases falling within 1, 2, and 3 standard deviations
from the mean on a normal distribution

Question 20

Z score

Answer 20

The values for a variable that have been transformed from their original “raw scores” into new “standardized” metric that has a mean of 0 and a standard deviation of 1
- A score that has been transformed into standard deviation units

Question 21

Correlation coefficient

Answer 21

Index indicating the strength and direction of linear relationship between two quantitative variables

• Correlation describes the strength
• Coefficient indicated the +/-, which describes the direction of the linear relationship

Question 22

Contingency table

Answer 22

Table used to examine the relationship between categorical variables