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Quant 2
Mid-term (ch. 8,9)
32
Business
Undergraduate 3
03/15/2008

Additional Business Flashcards

 


 

Cards

Term
Population
Definition
Contains all members about wish a study intends to make inferences
Term
Frame
Definition
A list of all members of the population
Term
Sampling Units  
Definition
Potential members of a sample from a population
Term
Judgemental Sample
Definition
Chosen by the samplers judgement and not by random
Term
Probability sample
Definition
Any sample that is chosen by random
Term
Simple Random Sample
Definition
A sample where each member of the population has the same chance of being chosen
Term
Systematic sample
Definition
A samoke where on eof the first K members is selected randomly, and then every Kth member after this one is selected
Term

Stratified Sample

 

What are the advantages? 

Definition

A sample where the population is divided into relatively homogeneous subsets (strata), and then random samples are taken from each of the strata

 

Advantages:

1) Separate estimates within each stratum

2) More accurate 

Term
Proportional sample sizes
Definition
Occurs when the proportion of each stratum selected is the same from stratum to stratum
Term

Cluster Sampling

 

 

Definition

A sample where the population is separated into clusters and then a random sample of the clusters is selected

 

Single Stage

Multistage (sample households) 

Term
Inference
Definition
A statement about a numerical characteristic of the population
Term
Sampling Error
Definition
inevitable: bad luck
Term
Nonsampling error
Definition

1) Nonresponse bias

 

2) nontruthful response  (fix by randomizing questions)

 

3)Measurement error ( the answers dont reflect the question the sampler intended)

 

4) voluntary response bias (only the A students respond 

Term
Point Estimate
Definition
"Best guess" of population parameter
Term
Estimation Error
Definition
Difference between the estimate of a population parameter and the true value of the parameter
Term
Sampling distribution
Definition
The distribution of the point estimates we would see from all possible samples from the population
Term
Confidence interval
Definition
An interval around the point estimate, calculated from the sample data, where we strongly believe the true value of the population parameter lies
Term
Unbiased Estimate
Definition
An estimate where the mean of its sampling distribution equals the value of the patameter being estimated
Term
Standard error of an estimate
Definition
The stdev of the sampling distribution of the estimate
Term
Mean of Sample Mean
Definition
Indicates unbiasedness of sample mean
Term
Standard error of the sample mean
Definition
Indicates how sample means from different samples vary
Term
Confidence interval for population mean
Definition
Very confident that the population mean is within this interval
Term
Finite Population Correction
Definition

A correction for the standard error when the sample size is fairly large relatively to the population size

 

WHEN MORE THAN 5% IS SAMPLED 

Term
Central Limit Theorem
Definition
The distribution of the sample mean is approximately normal for sufficiently large sample sizes
Term

Random Sample

 

What is the purpose? 

Definition
To estimate properties of a population
Term
Uniform Distribution
Definition
The resulting distribution where each value has the same chance of reoccuring
Term
Nuisance Parameter
Definition
You need the value even though the parameter is not a primary interest
Term
T-Distribution
Definition
The sampling distribution of the standardized sample mean when the sample standard deviation is used instead of the population strandard deviation
Term
T-Value
Definition
Indicates the number of standard errors that a sample mean differes from the population mean
Term

Confidence Levels

(Z) 

Definition
95%     1.96
90%     1.64
99%     2.59
Term

Confidence Levels

(T) 

Definition
95%     2.045
90%     1.699
99%     2.756
 
Term
Attribute Sampling
Definition
Checks if procedures are being followed
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