Q4 Examination Flashcards
occur when one or more parts of the population are favored over others
biased samples
only includes people who are easy to reach
convenience sample
consists of people that have chosen to include themselves
voluntary response sample
each individual has an equal chance to be chosen
draw lots
example: put names in the hat and selecting any of them (select 6) and interview them
simple random sampling (srs)
- can be divided into a “strata” that refers of group of several people within strata we select or take an SRS
- you can take 2 each in strata
divided into group
stratified random sample
we use a combination of two or more srs
stages
example: we have 3 groups, stage 1 could be selected
multistage sampling
used for population
parameter
used for samples
statistics
what are the 2 sampling method?
biased
unbiased
what are the 2 sample from biased?
- convenience sample
- voluntary response sample
what are the 3 sample from unbiased?
- simple random sampling
- stratified random sample
- multistage sampling
is a specific numerical estimate of a parameter
point estimator
an interval or range of values used to estimate the parameter
interval estimator
the computed estimate of a given sample size is equal to the parameter
unbiased estimator
as the sample size increases, the value of the estimate becomes nearer to the value of the parameter being estimated
consistent estimator
among all possible statistics that can be used to estimate a parameter, the estimator must have the smallest variance
relatively efficient
is the average.
The Mean
is how different each sample is.
The Variance
Deviation is how close the samples are
The Standard
- It tells us that as sample sizes gets larger, the sampling distribution of the mean will become normally distributed, even if the data within each sample are not normally distributed.
- If a random samples of size n are drawn from a population (finite or infinite), then as n becomes larger, the sampling distribution of the mean approaches the normal
distribution, regardless of the form of the population distribution.
CENTRAL LIMIT THEOREOM
A range of values that uses a point estimator but adds precision to estimate the parameter.
CONFIDENCE INTERVALS