Introduction and basic definitions

Question 1

What is Statistics?

Answer 1

A science involving the extraction of information from numerical data obtained during an experiment or from a sample

Question 2

What does method of practice does Statistics Involve?

Answer 2

1. The DESIGN of the experiment or sampling procedure,
2. collection of the data,
3. ANALYSIS of data,
4. and making INFERENCES (statements) about larger groups based on data collected.

Question 3

What is Population?

Answer 3

The entire group of individuals(subjects) about which the researcher wants info.

Question 4

What are 2 examples of Population?

Answer 4

1. All US citizens

2. All female students at the university

Question 5

What is Parameter?

Answer 5

Some Characteristics of the population that the researcher wants to measure.

Question 6

What are some examples of Parameter?

Answer 6

1. Proportion(part) of us citizens who voted in the last presidential election
2. Average (mean) height of all male students at this university
3. Proportion (Part) of all sections of all courses taught by part time faculty

Question 7

What does Proportion mean?

Answer 7

A part of the whole

Question 8

What does Average mean?

Answer 8

A number expressing the central value in a set of data

Question 9

In relation to Parameters, the Average or Mean of a population is indicated by what?

Answer 9

the Greek letter μ (mu). Looks like backward u or y

Question 10

In relation to Parameters, the Proportion (part) of a population that are “successes” is often indicated by what?

Answer 10

The greek letter π (PI)

Question 11

What is Sample?

Answer 11

A subset of the population that we examine in order to gather information

Question 12

What is an example of a Sample?

Answer 12

if population of university were all male students, then male students in a certain class would be a sample.

Question 13

What is a Statistic?

Answer 13

A descriptive measure, usually computed from a sample, which can be expressed or evaluated numerically.

Question 14

What is an example of Statistic?

Answer 14

if population was all male students, and male students in a class is the sample, then the AVERAGE HEIGHT of the male students would be a Statistic.

Question 15

In relation to Statistic, What is the Average or mean indicated by?

Answer 15

x̄ (X bar)

Question 16

In relation to Statistic the Proportion (part) of a sample that are successes are indicated by what?

Answer 16

p̂ (P-hat)

Question 17

What is an Inference?

Answer 17

A statement about a population based on the data collected in a sample.

Question 18

Example of an Inference

Answer 18

Using a sample statistic (like the average height in a class (x̄ )) to ESTIMATE a population parameter (an inferred answer for the whole group (μ ))

Question 19

What is Distribution?

Answer 19

A Listing of all possible values that a characteristic can take and the number (or percentage) of times.

Question 20

What is a major component of Statistics?

Answer 20

Describing the Distribution of a set of data.

Question 21

What is one example of Distribution?

Answer 21

1. consider gender of a student. students are either male or female.and if you count the number of each that’s the distribution.

Question 22

What are the two Branches of statistics you deal with usually?

Answer 22

Descriptive, and Inferential Statistics.

Question 23

What is Descriptive Statistics?

Answer 23

NUMERICAL AND GRAPHICAL techniques for describing characteristics of a population and comparing characteristics among populations

Question 24

What is Inferential Statistics?

Answer 24

where you use data and statistics computed from a sample to make inferences (statements) about a population.

Question 25

Often the inference in Inferential Statistics is based on some Descriptive Statistic that has already been computed or created?. T/F?

Answer 25

True. because based on the numerical or graphical data computed within descriptive statistics (usually from a sample of the pop) you are able to transfer that to inferential statistics to use that data to estimate a charecteristic about the population parameter (Average height)

Question 26

What is a goal of Statistics?

Answer 26

To measure some characteristics about a subject or a set of subjects.

Question 27

When using statistics what are two methods to assure accurate results?

Answer 27

REPLICATION AND REPETITION

1. replicating trials and measure the characteristic on several subjects. (sample)
2. if only one subject, repeat measurements several times

Question 28

What is repetition/replication?

Answer 28

repeating measurement for more accurate result. it is in repeated experiments that statistics become important

Question 29

it is in repeated experiments that statistics become important? T/F?

Answer 29

True

Question 30

What is a Constant?

Answer 30

Measurement of some characteristic does not change in repeated trials over time.

Question 31

Example of a Constant?

Answer 31

1. Number of days in January each year? Always 31

2. Number of minutes in an hour? Always 60

Question 32

What is a Variable?

Answer 32

When measurements of characteristics vary/change from trial to trial.

Question 33

Examples of a Variable?

Answer 33

1. Height of student

2. Grades on tests

Question 34

In statistics we are not primarily concerned with the observation of variables? T/F

Answer 34

F. We are primarily concerned with the observation of variables. Reason being, of we know what they measurment is going to be there is no reason for repeated experiments but that is seldom

Question 35

What two Categories are variables classified in?

Answer 35

Qualitative and Quantitative.

Question 36

What is a Qualitative Variable?

Answer 36

May vary in name or size, but not in degree (level)/ no order or ranking applied

Question 37

What are three examples of a Qualitative Variable?

Answer 37

1. Gender- male or female
   2 Eye color- any kind
   SSN- A number that is used to identify a person

Question 38

What is a Quantitative Variable?

Answer 38

measurements vary in size from trial to trial. some order or ranking can be applied.

Question 39

Examples of Quantitative Variable?

Answer 39

1. # of students in a particular class
2. weight of a typical student
3. grades on tests

Question 40

What are the two subsets of Quantitative Variables?

Answer 40

Discrete, and Continuous.

Question 41

What is a Discrete Quantitative Variable?

Answer 41

Measurements can assume only a COUNTABLE # of possible values.

Question 42

What are some examples of a Discrete Quantitative Variable?

Answer 42

1. # of students in a particular class
2. Number of cars in parking deck
3. Grades on a test

Question 43

What is a Continuous Quantitative Variable?

Answer 43

measurement can assume any one of a countlessnumber of values in a line interval. usually something measured or calculated like rates averages proportions percentage.

Question 44

What are some examples of a Continuous Quantitative Variable?

Answer 44

1. Weight of a typical students

2. percentage of students who pass the course.

Question 45

In most problems the data that we have is what?

Answer 45

a sample of the population

Question 46

What is the goal for using the sample data?

Answer 46

Apply it and make statements about the population as a whole

Question 47

What letters will be used to indicate Parameters and what letters will be used to indicate Statistics?

Answer 47

1. Greek letters indicate parameters

2. English letters indicate Statistics

Question 48

The type of analysis to be performed is dependent on what?

Answer 48

The type of data collected. Hence being able to identify whether a variable is qualitative or quantitative. o assure the appropriate analysis is done.