Targets 1A-1F

Question 1

Variable

Answer 1

A characteristic that changes from one individual to another

Question 2

Categorical Variable

Answer 2

Takes on values that are category names or group labels

Question 3

Quantitative Variable

Answer 3

takes on numerical values for a measured or counted quantity; an average makes sense

Question 4

Distribution

Answer 4

shows the values of a variable and their frequencies; distributions may be displayed in tables or graphs

Question 5

Frequency Table

Answer 5

gives the number of cases falling into each category

Question 6

Relative Frequency Table

Answer 6

gives the proportion of cases falling into each category
Percentages, relative frequencies, and rates all provide the same information as proportions.

Question 7

Pie Graphs

Answer 7

less favored because it is more difficult to
estimate the proportion occupied by each section of the
pie if the wedges are not clearly labeled

Question 8

Area Principle

Answer 8

the area occupied by a part of a graph must
correspond to the magnitude of the value it represents

Question 9

Requirements for Graphs

Answer 9

ALL graphs must have a title, word labels and number labels
on both axes and constant increments on the axes.
** It is important that you include these on any graph you create.
** It is equally important that you observe these on any graph you read.

Question 10

Bar Chart

Answer 10

displays frequencies or relative frequencies (percentages) for categorical data
Vertical axis – labeled as counts, frequencies or relative frequencies
Horizontal axis – labeled with the possible values (categories) of the variable
There are spaces between the bars because the categories could be shown in any order.

Question 11

Requirements to compare two distributions of data

Answer 11

the axes on both graphs must be expressed as proportions and
the graphs must have identical axis numbering and labeling.

Question 12

Discrete Variable

Answer 12

can take on a countable number of values; Ex # siblings, # home runs

Question 13

Continuous Variables

Answer 13

can take on infinitely many values; Ex: GPA, height, length of time

Question 14

Dotplot

Answer 14

a dot is placed above the x-axis for each data value; only the horizontal axis is labeled

Question 15

Uniform

Answer 15

• last digits of phone numbers
• last digits of ID numbers
• outcomes from random
events where all outcomes are
equally likely

Question 16

Bimodal

Answer 16

• hair length
• distributions with two
subgroups
• duration of the eruptions of
Old Faithful geyser
Describe TWO centers, not one.

Question 17

Unimodal Symmetric

Answer 17

• biological measurements
• IQ scores

Question 18

Unimodal Skewed Left

Answer 18

• scores from an easy test

Question 19

Unimodal Skewed Right

Answer 19

• salaries in a large company or
on a professional sports team
• home values

Question 20

Describing a Distribution (SOCSI)

Answer 20

Shape – modes and symmetry
Outliers, Gaps, Clusters
Center – specify the mean or the median
Spread – specify the standard deviation or the IQR
In Context!!! State the variable you’re describing and use units!

Question 21

Stemplot

Answer 21

typically, stems represent the tens’ place and the leaves represent
the ones’ place; there MUST be a legend and a title; the shape of the
distribution can be seen by carefully turning the stemplot sideways

Question 22

Histogram

Answer 22

displays the values of one variable sorted into bins
There are no spaces between the bars because the horizontal axis cannot be rearranged.
Horizontal axis – a number line with equal increments
Vertical axis – frequency or relative frequency
6 – 10 bins are optimal; adjusting the bin width can help to better visualize the distribution