The paired sample z-test or t-test (for low observations) is used to compare "paired" data across time. A popular homework help for paired sample tests is comparing before and after treatment data of the same participants. This data is not independent because it is largely based on the participants. Assignment help of this kind is submitted regularly for studies in psychology and medicine. Nonparametric alternatives to this test are available, such as the Paired-Sample Sign Test and the Wilcoxon Signed Rank Test.
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