QU1 Chapter 1

Question 1

Why does a manager need to know about statistics

Answer 1

1. to know how to properly present information
2. to know how to draw conclusions about populations based on sample information
3. to know how to improve processes
4. to know how to obtain reliable forecasts

Question 2

What is the growth of development of modern stats?

Answer 2

1. needs of government to collect data on its citizenry
2. which lead to the development of the mathematics of probability theory
3. the evolution of electronic computing

Question 3

definition of population:

Answer 3

(universe) is a collection of things under consideration

Question 4

Definition of sample

Answer 4

portion of the population elected for analysis

Question 5

definition of parameter

Answer 5

summary measure computer to describe a characteristic of the population

Question 6

definition of statistic

Answer 6

summary measure computed to describe a characteristic of the sample

Question 7

definition: descriptive statistics

Answer 7

collection, presentation and characterization of data

Question 8

Definition: Inferential Statistics

Answer 8

estimation of a characteristic of a population or drawing conclusions concerning a population based only on sample results.

Question 9

What is descriptive Statistics - eData collection, presentation and characterization

Answer 9

data collection - survey
data presentation - tables and graphs
data characterization - eg. sample mean

Question 10

describe mean average and

Answer 10

need more

Question 11

Describe inferential statistics

Answer 11

estimation - eg. estimate the population mean weight using the sample mean weight
Hypothesis testing - eg. test the claim that the population mean weight is 120 pounds
(draw conclusions and /or making decisions concerning a population based on sample results)

Question 12

Why is data needed?

Answer 12

1. to provide input to survey
2. to provide input to study
3. to measure performance of service or production process
4. to evaluate conformance to standards
5. to assist in formulating alternative courses of action
6. to satisfy curiosity

Question 13

What are the two data sources

Answer 13

1. primary data collection

2. Secondary data compilation

Question 14

What does primary data collection consist of

Answer 14

1. observation
2. Survey
3. experimentation

Question 15

what does secondary data compilation consist of

Answer 15

print or electronic

Question 16

what is a random variable

Answer 16

definition of possible outcomes of interest form an experiment

Question 17

what are the types of random variables

Answer 17

1. categorical (qualitative)

2. Numerical (quantitative)

Question 18

What are the two types of numerical (quantitative)

Answer 18

1. Discrete (counting)

2. Continuous (Measuring)

Question 19

what are the reasons why we want to draw a sample

Answer 19

1. less time consuming than a census
2. less costly than a census
3. less cumbersome and more practical to administer than a census of the targeted population

Question 20

What are the types of sampling methods

Answer 20

1. Non-probability samples

2. Probability samples

Question 21

what are the probability samples

Answer 21

1. simple random
2. systematic
3. stratified
4. cluster

Question 22

what are the Non-probability samples

Answer 22

1. Judgement
2. quota
3. Chunk

Question 23

What is a simple random (watch a video) need more detail (replacement or replacement???)

Answer 23

• every individual or item form the frame has an equal chance of being selected
• selection may be with replacement or without replacement
• samples obtained from a table of random number for computer random number generators

Question 24

What is systematic

Answer 24

1. Decided on sample size : n
2. divided frame of N individuals into groups of k individuals: k= N/n
3. randomly select one individual from the 1st group
4. select every k-th individual thereafter

Question 25

What is a stratified sample

Answer 25

1. population divided into two or more groups according to some common characteristic 2. simple random sample selected form each group the two or more samples are combined into one

Question 26

What is cluster

Answer 26

1. population divided into several "Clusters" each representative of the population 2. simple random sample selected from each 3. the samples are combined into one

Question 27

what are the advantages and disadvantages of simple random sample

Answer 27

- simple to use | - may not be a good representation of the population's underlying characteristics

Question 28

what are the advantages and disadvantages of stratified sample

Answer 28

ensures representation of individuals across the entire population

Question 29

what are the advantages and disadvantages of cluster sample

Answer 29

- more cost effective | - less efficient (need larger sample to acquire the same level of precision)

Question 30

what are some questions to ask when evaluating survey wrothiness

Answer 30

1. what is the purpose of the survey 2. is the survey based on probability sample? 3. coverage error - appropriate frame? 4. non-response error - followed up? 5. measurement error - good questions elicit good responses 6. sampling error - always exists. reduced by taking large samples

Question 31

what are the types of survey errors

Answer 31

1. coverage error 2. non response error 3. sampling error 4. measurement error

Question 32

what is coverage error

Answer 32

certain groups are excluded from the frame, therefore they have no chance of being included

Question 33

what is non response error

Answer 33

- must follow up with non responses

Question 34

what is sampling error

Answer 34

chance differences form sample to sample

Question 35

what is measurement error

Answer 35

bad question, leading questions must be avoided Halo effect and respondent error - overzealous or under zealous efforts by the respondend

Question 36

what is data

Answer 36

data is a set of numbers that represent some type of metric or measurement

Question 37

what is information

Answer 37

information is what the data means

Question 38

Descriptive statistics according to cga

Answer 38

how data is organized, described and presented - statistics such as mean (average), variance, range etc. - organized and presented using tables, charts etc.

Question 39

Inferential statistics according to CGA

Answer 39

drawing conclusions about the population based on the sample's data