Ch 1; Picturing Distributions w/ Graphs

Question 1

Statistics

Answer 1

Science of leaning from data.

Question 2

Any set of data contains…

Answer 2

Information, organized in variables, about some group of individuals.

Question 3

Individuals

Answer 3

The objects described by a set of data. (People, animals, things)

Question 4

Variable

Answer 4

Any characteristic of an individual.

Question 5

Data

Answer 5

Actual measurements of variables recorded for individuals. (Numbers, pieces of info)

Question 6

2 Types of Variables

Answer 6

Quantitative, Qualitative/Categorical

Question 7

Categorical Variables

Answer 7

Places individuals into one of several groups (gender)

Question 8

Quantitative Variable

Answer 8

Takes numerical values for which arithmetic operations can be used. (Often has units)

Question 9

2 Types of Categorical Variables & Examples

Answer 9

Ordinal (Size, blood group, performance, pain ratings)(Scaled), Nominal (Colour, gender)

Question 10

2 Types of Quantitative Variables & Examples

Answer 10

Continuous (2.31, 4.25), Discrete (0,1,2)

Question 11

Exploratory Data Analysis

Answer 11

Process of using statistical tools & ideas to analyze data in order to describe main features.

Question 12

Steps to Exploratory Data Analysis

Answer 12

1) Examine Each Variable
2) Examine relationships b/w variables
3) Graph
4) Add numerical summaries of specific aspects of data

Question 13

Distribution of a Variable

Answer 13

Values it takes & how often it takes these values

Question 14

What does a Distribution of a Categorical Variable do?

Answer 14

Lists categories & gives either percents/count of individuals in each category. (Values are labels of categories)

Question 15

Best Graphs for Categorical Variables (2)

Answer 15

Pie Chart, Bar Graphs

Question 16

Pie Chart

Answer 16

Shows distribution of categorical data as pie where slices are sized by counts/percents for categories of a whole. (Single Whole)

Question 17

Bar Graph

Answer 17

Each category is a bar whose height shows category counts/% (Single variable/variables from different sources not part of a whole)

Question 18

Best Graphs for Quantitative Variables (3)

Answer 18

Histograms, Stemplots, Time Plot

Question 19

Histogram

Answer 19

Show distribution of quantitative variables by using bars whose heights represent #/frequency of individuals who take on a value within a particular class (Range of #s).

Question 20

Stemplot

Answer 20

Separate each observation into a stem & a leaf that are then plotted to display distribution while maintaining the original values of variable.

Question 21

What to look for when Describing Distributions

Answer 21

Look for patterns & striking deviations from pattern

Question 22

How can you Describe Pattern (4)

Answer 22

Shape, Center, Variability, Outliers (Individual values that fall outside of pattern)

Question 23

Shapes of a Distribution (3)

Answer 23

Symmetric; Right & left mirror images
Right Skewed; Long tail on right
Left Skewed; Long Tail on left
Bimodal; 2 bumps

Question 24

Time Plot

Answer 24

Shows behavior over time (Time on horizontal axis & measured variable on vertical axis)