Review 4 Flashcards
Unbiased Sample
All members in the population have an equal chance of being sampled, therefore, each member should be proportionately represented in the sample ( also known as simple random sample)
Stratified Sampling
The population is subdivided into 2 or more different subpopulations (strata)
Systematic Sampling
Choose a random starting point and then select every n’th element in the population
Cluster Sampling
Divide the population into clusters (sections) and then randomly select some clusters and sample all members of those clusters
Convenience Sampling
Use results that already available
Hypothesis Test
- State the hypothesis
- Choose level of significance
- Calculate the appropriate test statistic from the sample data and compare to the distribution’s critical value from a table
- Reject or fail to reject H0 based on the decision rule
- Base your decision on the p-value
Null Hypothesis
A statement which is considered to be true until proven false by the sample data
Alternative hypothesis
A statement which is accepted as tru IF the null hypothesis is proven to be false
Type I Error
Occurs with probability alpha. Happens when you reject the null hypothesis when in fact it is true.
Type II Error
Occurs with type beta. Happens when you fail to reject the null hypothesis when in fact it is false
Significance Level (alpha)
0.1, 0.5 or .10
P-value
The smallest level at which H0 can be rejected for a given set of data
Rejection Region
Tail area(s) of the sampling distribution
associated with the hypothesis test
Non-rejection region
Everything not shaded by tails of sampling distribution
Test Statistic
calculated value
