S2 Flashcards
Define a sample
A selection of individual items from a population
Define a sampling unit
An individual item of a population
Define a sampling frame
A list of sampling units used in practice to represent a population
Define a statistic
A quantity calculated from the observations in a sample
What’s a sampling distribution
All possible values of the statistic and the probability of each occurring
Define population
Collection of individual items
Census
An investigation where information is obtained from all members of a population
Hypothesis
A statement made about the value of a population parameter that we wish to test by collecting evidence in the form of a sample.
Test statistic
Evidence from a a sample which is summarised in the form of a statistic
Null hypothesis Ho
The hypothesis we assume to be correct
Alternative hypothesis, H1
The value of the population parameter if our assumption is shown to be wrong
Critical region
Range of values of the test statistic that would lead you to rejecting Ho
Critical values
The boundaries of the critical region
Actual significance level
The probability of rejecting Ho in the test
A simple random sampling of size n
Is one so that every possible sample size of n has an equal chance of being selected
