Inferential Statistics Flashcards
To make a decision about the population group based on the information of the sample group
Inferential Statistics
Population
The complete collection to be studied
Sample
part of the population of interested selected for the study
Sampling errors
differences between the sample values and population values
Sample selection is required to be __
random
random selection implies all members have an equal opportunity to be chosen
doesnβt guarantee proportional representation of all parts of the population
Sampling distribution of a statistic
distribution of values taken by the statistic in all possible samples of the same size from the same population
Sampling distribution of means
distribution of sample means. Called standard error of the mean.
Sampling distribution of means formula
π /βπ
where n = sample size
Common use of Inferential Statistics
estimate population parameters
compare between groups
SHT procedure
- state statistical hypotheses (null and alternative)
- Select level of significance
- Decide which test to use
- Make a decision to reject or retain null hypothesis based on p value
p value
major resulting value of running a SHT
quantifies how consistent your sample values are with null hypothesis
ranges from 0-1
large p value
closer to 1:
sample values are consistent with null hypothesis
small p-value
closer to 0:
sample values are not consistent with null hypothesis
how to make decision to reject or retain null hypothesis based on p value and πΌ
compare p value to preset level of significant (πΌ).
if πΌ= 0.05 and p value < 0.05, reject null hypothesis
if p value > 0.05 retain null hypothesis.
if p > .05 you can decide that
observed difference is not significant