ISDS CH. 7

Finite Population Correction Factor

A correction factor that accounts for the added precision gained by sampling a larger percentage of the population. It is implemented when the sample constitutes at least 5% of the population

What are the disadvantages to Cluster Sampling?

Less precision

Population

consist of all items of interest in a statistical problem

Cluster Sampling

dividing the population into groups such as geographic areas and then selecting a sample of the groups for the analysis

Central Limit Theorem

states that the sum or mean of a large number of independent observations from the same underlying distribution has an approximate normal distribution

Statistical Quality Control

statistical technique used to develop and maintain a firm's ability to produce high-quality goods and services

Stratified Random Sampling

the population is divided into groups (strata) based on one or more classification criteria

Nonresponse Bias

this occurs when those responding to a survey or poll differ systematically from the nonrespondents

Acceptance Sampling

used at the completion of a production process or service; if a particular product does not conform to certain specifications, then it is either discarded or repaired

What are the Disadvantages to Acceptance Sampling?

1. Costly to discard or repair a product 2. the detection of all defective products is not guaranteed

What are the two advantages to Stratified Random Sampling?

1. guarantees that the population subdivisions of interest are represented in the sample 2. the estimates of parameters produced from stratified random sampling have greater precision than estimates obtained from simple random sampling

What are the advantages to Cluster Sampling?

1. less expensive 2. useful when clusters occur naturally in the population

Selection Bias

refers to a systematic underrepresentation of certain groups from consideration of a sample

Bias

refers to the tendency of a sample statistic to systematically overestimate or underestimate a population parameter

Detection Approach

inspection occurs during the production process in order to detect any nonconformance to specifications - the goal is to determine whether the production process should be continued or adjusted before producing a large number of defects

Simple Random Sample

is a sample of "n" observations that has the same probability of being selected from the population as any other sample of "n" observations

Sample

is a subset of the population

The central limit theorem states that, for any distribution, as n gets larger, the sampling distribution of the sample mean ____________.

is closer to normal distribution

Social Desirability Bias

occurs when voters provide incorrect answers to a survey or poll because they think that others will look unfavorable on their ultimate choice