Summer Work Vocab

Question 1

individuals

Answer 1

the objects described by a set of data. Individuals may be people, animals, or things.

Question 2

variable

Answer 2

any characteristic of an individual. A variable can take different values for different individuals.

Question 3

categorical variable

Answer 3

places an individual into one of several groups or categories.

Question 4

quantitative variable

Answer 4

takes numerical values for which it makes sense to find an average.

Question 5

discrete variables

Answer 5

a variable can’t take on any value between its minimum value and its maximum value

Question 6

continuous

Answer 6

a variable can take on any value between its minimum value and its maximum value

Question 7

univariate data

Answer 7

a study that looks at only one variable

Question 8

bivariate data

Answer 8

a study that examines the relationship between two variables

Question 9

population

Answer 9

the total set of observations that can be made

Question 10

sample

Answer 10

a set of observations drawn from a population

Question 11

census

Answer 11

a study that obtains data from every member of a population

Question 12

distribution

Answer 12

what values the variable takes and how often it takes these values.

Question 13

inference

Answer 13

drawing conclusions that go beyond the data at hand.

Question 14

frequency table

Answer 14

a table that shows frequency counts for a categorical variable

Question 15

relative frequency table

Answer 15

a table that shows relative frequencies for different categories of a categorical variable

Question 16

roundoff error

Answer 16

the difference between the result produced by a given algorithm using exact arithmetic and the result produced by the same algorithm using finite-precision

Question 17

pie chart

Answer 17

show the distribution of a categorical variable as a “pie” whose slices are sized by the counts or percents for the categories. A pie chart must include all the categories that make up a whole.

Question 18

bar graph

Answer 18

represent each category as a bar. The bar heights show the category counts or percents.

Question 19

two-way table

Answer 19

organizes data about two categorical variables measured for the same set of individuals.

Question 20

marginal distribution

Answer 20

the distribution of values of that variable among all individuals described by
the table.

Question 21

conditional distribution

Answer 21

describes the values of that variable among individuals who have a specific value of another variable. There is a separate conditional distribution for each value of the other variable.

Question 22

segmented bar graph

Answer 22

one kind of stacked bar chart, but each bar will show 100% of the discrete value

Question 23

side-by-side bar graph

Answer 23

bar chart where segments are placed next to each other

Question 24

association

Answer 24

knowing the value of one variable helps predict the value of the other.

Question 25

Simpson’s paradox

Answer 25

a trend appears in several different groups of data but disappears or reverses when these groups are combined

Question 26

dotplot

Answer 26

a graph where each data value is shown as a dot above its location on a number

Question 27

shape

Answer 27

describes the visual pattern of a distribution

Question 28

mode

Answer 28

most common value

Question 29

center

Answer 29

midpoint of a set of values

Question 30

spread

Answer 30

how much the data varies

Question 31

range

Answer 31

how spread the data is

Question 32

outlier

Answer 32

an individual value that falls outside the overall pattern.

Question 33

symmetric

Answer 33

if the right and left sides of the graph are approximately mirror images of each other.

Question 34

skewed right

Answer 34

the right side of the graph (containing the half of the observations with larger values) is much longer than the left side.

Question 35

skewed left

Answer 35

the left side of the graph is much longer than the right side.

Question 36

unimodal

Answer 36

a distribution having a single peak

Question 37

bimodal

Answer 37

a distribution having 2 peaks

Question 38

multimodal

Answer 38

distributions with more than 2 peaks

Question 39

stemplot

Answer 39

separate each observation into a stem and a one-digit leaf.

Question 40

splitting stems

Answer 40

dividing information in stemplots into multiple “stems” or components

Question 41

back-to-back stemplots

Answer 41

a method for comparing two data distributions by attaching two sets of ‘leaves’ to the same ‘stem’ in a stemplot

Question 42

histogram

Answer 42

plot the counts (frequencies) or percents (relative frequencies) of values in equal-width classes.

Question 43

mean

Answer 43

measure of center found by adding a set of values

and dividing by the number of observations.

Question 44

median

Answer 44

The median is the midpoint of a distribution, the number such that about half the observations are smaller and about half are larger.

Question 45

interquartile range (IQR)

Answer 45

The interquartile range (IQR) measures the range

of the middle 50% of the data.

Question 46

five-number summary

Answer 46

The five-number summary of a distribution consists of the smallest observation, the first quartile, the median, the third quartile, and the largest observation, written in order from smallest to largest.

Question 47

boxplot

Answer 47

a graph made by the five number summary of a distribution

Question 48

standard deviation

Answer 48

measures the typical distance of the values in a distribution from the mean. It is calculated by finding an average of the squared deviations and then taking the square root.

Question 49

variance

Answer 49

the squared standard deviation