Chapter 1 Vocab

Question 1

Data Analysis

Answer 1

Organizing, displaying, summarizing and asking questions about a certain topic.

Question 2

Individuals

Answer 2

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

Question 3

Variable

Answer 3

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

Question 4

Categorical Variable

Answer 4

Places an individual into one of several groups or categories. (Variables that take on values that are names or labels)

Question 5

Quantitative Variable

Answer 5

Variables that have are measured on a numeric or quantitative scale. (Takes numerical values for which it makes sense to find an average).

Question 6

Distribution

Answer 6

The pattern of variation of a variable. Tells us what value a variable takes and how often it takes it.

Question 7

Inference

Answer 7

Draws conclusions that go beyond the data at hand.

Question 8

Frequency Table

Answer 8

Displays the counts (frequencies) of stations in each format category.

Question 9

Relative Frequency Table

Answer 9

Shows the percent (relative frequencies) of stations in each format category.

Question 10

Roundoff Error

Answer 10

The difference between an approximation of a number used in computation and its exact value (the difference between its number value and the percentage it represents)

Question 11

Pie Chart

Answer 11

Show the distribution of a categorical variable as a “pie” whose slices are sized by the counts or percents for the categories.

Question 12

Bar Graph

Answer 12

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

Question 13

Two-Way Tables

Answer 13

The observed number or frequency for two variables, the rows indicating one category and the columns indicating the other category.

Question 14

Marginal Distribution

Answer 14

(Of one of the categorical values in a two-way table) is the distribution of values of that variable among all individuals described by the table. Essentially the row and column totals in a two-way table.

Question 15

Conditional Distribution

Answer 15

Describes the values of a variable among individuals who have a specific value of another variable. There is a separate conditional distribution for each value of the other variable. Also known as Ditional Distribution.

Question 16

Side by Side Bar Graph

Answer 16

A bar graph representing 2 separate categorical values, of which are represented separately across the x-axis by different colors and are placed next to each other, making it easier to read between the two groups.

Question 17

Segmented Bar Graph

Answer 17

Used for grouping or categorizing the parts of a whole. The bars in this chart are categorized into stacking order to represent different values. The bar segments within a category bar are placed on top of each other. Different colors will show distinctive parts of the whole bar.

Question 18

Association

Answer 18

The relation that two variables share. The term “association” is used between two variables when knowing the value of one variable helps predict the other variable’s value.

Question 19

Dotplot

Answer 19

A graph that displays quantitative data by showing each data value as a dot above its location on the number line.

Question 20

Overall Pattern

Answer 20

Describes the distribution by the shape, center and spread of the data.

Question 21

Departures

Answer 21

An individual value that falls outside the overall pattern.

Question 22

Center

Answer 22

Center is the median and/or mean of the data.

Question 23

Spread

Answer 23

The spread is the range of the data.

Question 24

Shape

Answer 24

The shape describes the type of graph. The four ways to describe shape are whether it is symmetric, how many peaks it has, if it is skewed to the left or right, and whether it is uniform.

Question 25

Outlier

Answer 25

A data point that differs significantly from other observations.

Question 26

Mode

Answer 26

The most common value of a data set.

Question 27

Symmetric Distribution

Answer 27

When the right and left sides of the graph are approx. mirror images of each other.

Question 28

Right-Skewed Graph

Answer 28

Where the tail of the graph is on the right side, if the right side of the graph (containing the half of the observations with larger values) is much longer than the left side.

Question 29

Left-Skewed Graph

Answer 29

Where the tail of the graph is on the left side, if the left side of the graph (containing the half of the observations with larger values) is much longer than the right side.

Question 30

Unimodal Dot Plot

Answer 30

A dot plot in which there is only one peak

Question 31

Bimodal Dot Plot

Answer 31

A dot plot in which there are two peaks

Question 32

Stemplot

Answer 32

A plot where each data value is split into a “leaf” (usually the last digit) and a “stem” (the other digits). Stems are written in a vertical column with the smallest at the top to the largest at the bottom, where no stem is skipped, even if there is no data value. A vertical line is written at the right of this column, for the “leaf” is to be written to the right of the line. The “leaf” on the right side are arranged in numerical order, increasing in number from the stem. (Ex: [5|2 4] represents the values of 52 and 54).

Question 33

Stem

Answer 33

All digits but the final (ones) digit

Question 34

Leaf

Answer 34

The final (ones) digit

Question 35

Splitting Stems

Answer 35

A method used to more accurately represent data using a stemplot, therefore making it easier to identify the shape of the plot. Separates the “leaf” values from 0-4 and 5-9 on separate stems of the same value.

Question 36

Back-to-Back Stemplot

Answer 36

A stemplot used for representing two sets of categorical data. This is done by representing one set of data’s “leaf” values on the left from the stem, and one set of data on the right.

Question 37

Histogram

Answer 37

A diagram consisting of rectangles whose area is proportional to the frequency of a variable and whose width is equal to the class interval. Displays the distribution of a quantitative variable.

Question 38

Mean

Answer 38

The average of the data set. Also known as “x bar”(x̅), and represented by the letter x with a horizontal line above it. Found by adding all of the data points and dividing by the amount of points that were added. Formula in compact notation is x̅ = ∑xi / n

Question 39

Resistant Measure of Center

Answer 39

Identifies if the measure of center is affected by outliers. If it is affected, it isn’t a resistant measure of center. If it isn’t affected, it is a resistant measure of center.

Question 40

Median

Answer 40

The midpoint of a distribution, the number such that about half the observations are smaller and about half are larger. Arrange all observations in order of size, from smallest to largest. If the number of observations n is odd, the median is the center observation in the ordered list. If the number of observations n is even, the median is the average of the two center observations in the ordered list.

Question 41

Range

Answer 41

Shows the full spread of the data. Calculated by subtracting the smallest number in the data set from the largest number in the data set. Could be less accurate due to outliers.

Question 42

First Quartile

Answer 42

The median of the observations that are to the left of the median in the ordered list.

Question 43

Third Quartile

Answer 43

The median of the observations that are to the right of the median in the ordered list.

Question 44

Interquartile Range

Answer 44

(Q3-Q1) Is a measure of statistical dispersion, being equal to the difference between 75th and 25th percentiles.

Question 45

1.5 Outlier Rule

Answer 45

This rule uses the first and third quartile values as well as the IQR to calculate outliers in the data set. The rule is: if a data point is less than (Q1- 1.5 x IQR) or more than (Q3+ 1.5 x IQR), it is an outlier.

Question 46

Five Number Summary

Answer 46

A set of 5 numbers that show the overall spread and diversity of a data set. The 5 numbers are: the minimum data point, the first quartile, the median, the third quartile, and the maximum data point (in that order).

Question 47

Boxplot

Answer 47

A graph that is formed by the 5 number summary, creating a visual on a number line that shows the quarters of the data set. A boxplot is arranged above a number line, with a central box drawn from the first quartile (Q1) to the third quartile (Q3), and a line inside the box to mark the median. Lines (called whiskers) extend from the box out to the smallest and largest observations that are not outliers. Outliers are marked with a special symbol like an asterisk.

Question 48

Deviation

Answer 48

The distance a data point is from the mean of the set. (xi-x̄)

Question 49

Variance

Answer 49

The expectation of the squared deviation of a random variable from its mean. The average of the squared deviations. Formula: (S2 = ∑(xi-x̄)/n-1) Variance is also represented by (s2x).

Question 50

Standard Deviation

Answer 50

The “typical” distance of the values in the data set from the mean. Formula: (Standard Deviation = √variance) Standard deviation is also represented by (sx).