Chapter 5:
Statistical Inference (part 2)
Two Sample Hypothesis Tests
Comparing two populations for differences in means, proportions or other population parameters
ex:-confirm differences between suppliers
-effect of two medications on curing an illness
Dependent vs. Independent Sample
independent
dependent
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Samples are related to each other
Occur in two scenarios (post test and pre test/ before and after)
Scores on a test before and after the lesson
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Samples are selected at random
The scores of one samples does not affect the other
Waiting time in Hospital A vs Hospital B
Two sample test for mean/Independent group
One tailed test (Lower-tailed)
One tailed test (upper-tailed)
Two tailed test
H0 : µ1 - µ2 > 0
H1 : µ1- µ2 < 0
H0 : µ1 - µ2 = 0
H1 : µ1- µ2 ≠ 0
H0 : µ1 - µ2 < 0
H1 : µ1- µ2 > 0