Chapter 11 Flashcards
The independent requirement means that cases in a
sample are selected independently of each other
With a 2-sample case the sample outcome is the
difference between the sample statistics
sampling distribution of 2 cases =
all possible differences in mean income
If the null hypothesis is true the difference will be
zero
Which steps are affected when the population SD in unknown
1, 3, and 4
what does assuming the variances of the populations are equal mean
measn the ratio of sample size should be 2.0 or less
EX: N1=150 N2-100 150
————- = 1.5
100
How to find DF when population SD is unknown
n1+n2-2
what is the pooled estimate of the population proportion symbol
Pµ
if individual confidence intervals for each mean don’t overlap
we reject the null hypothesis
if confidence intervals over lap the difference between the sample means are
not statistically significant and can’t be used to rely on
What does Cohens d describe
the importance of magnitude of difference between two means
Cohens d converts the difference between 2 means into units of
SD
Cohens d effect size
small= 0-0.19
medium= 0.2-0.8
large= more than 0.8
