Chapter 1: Introduction

Question 1

Population

Answer 1

All members of a well defined group

Question 2

Parameter

Answer 2

A characteristic of a population

Question 3

Sample

Answer 3

Consisting of a subset of a population

Question 4

Statistic

Answer 4

Characteristic of a sample

Question 5

Descriptive Statistics

Answer 5

Techniques which allow us to tabulate, summarize, and depict a collection of data in an abbreviated fashion.

The purpose of which is to allow us to talk about (describe) a collection of data without having to look at the entire collection

Question 6

Inferential Statistics

Answer 6

Techniques which allow us to employ inductive reasoning to infer the properties of an entire group or collection of individuals, a population, from a small number of those individuals (a sample).

Question 7

Variable

Answer 7

Any characteristic of persons or things that is observed to take on different values (varies)

Question 8

Constant

Answer 8

Any characteristic of persons or things that is observed to take on only a single value

Question 9

Categorical Variable

Answer 9

Qualitative variable that describes categories of a characteristic or attribute. Like political party affiliation (1=Republican, 2=Democrat, 3=Independent, etc)

Question 10

Dichotomous Variable

Answer 10

A special, restricted type of categorical variable defined as a variable that can only take on one of two values (male/female, true/false, pass/fail, living/dead, smoker/nonsmoker)

Question 11

Numerical Variable

Answer 11

A quantitative variable. Either discrete or continuous

Question 12

Discrete Variable

Answer 12

A variable that can only take on certain values. Like number of children in a family, you can’t have -2 and you can’t have 3.7

Question 13

Continuous Variable

Answer 13

A variable that can take on any value within a certain range given a precise enough measurement instrument. Distance between cities can be measures in miles, but given a more precise measurement tool, you could measure in inches.

Question 14

What’s the difference between Continuous and Discrete variables?

Answer 14

Discrete arise from the counting process. Continuous comes from the measuring process.

Question 15

Measurement

Answer 15

The assignment of numerical values to persons or things according to explicit rules

Question 16

Nominal Scale

Answer 16

Individuals or objects are classified into categories so that all of those in a single category are equivalent with respect to the characteristic being measured

Question 17

Ordinal Scale

Answer 17

Determined by the relative size or position of of individuals or objects with respect to the characteristic being measured. Rank ordered.

For example, think of your rank in class. You know that 1 is 9 places ahead of 10th, but that doesn’t tell you the difference between their performance, you don’t know if it was a big gap or small. Student 250 might be further from student 249 than student 2 from student 1.

Question 18

Interval Scale

Answer 18

Individual objects can be ordered, and equal distances between the values do imply equal distance relationships are meaningful. No absolute zero, therefore you can’t say 60 degrees is twice as warm as 30 degrees. Considered numerical and primarily continuous.

Question 19

Ratio Scale

Answer 19

All the properties of an interval scale except there is an absolute zero point, a complete absence of what is being measured. Numerical and can be discrete or continuous.