Statistical Inference Flashcards
statistical inference
deduce broad conclusions about the population from which a sample has been obtained
point interval
derived from the corresponding sample parameters e.g. the mean and the standard deviation
confidence interval
range which we would expect, with a given level of confidence to include the population parameter
inferences about sample means are based on normal distribution if:
- sample has been selected from a normal population, with a known SD or the sample size is large
- observations in the sample are independent i.e. sample is random and no member is included more than once
as the number in the sample increases…
the distribution of the sample proportion tends to normality
type I error
reject a true null hypothesis (i.e. you think there is a significant relationship when there is not)
type II error
accept a false null hypothesis (i.e. you think there isn’t a relationship, when in fact there is)
test statistic
to test the difference between the observed and hypothesised