Question

Relating to the conditions of a t-test, why is it important to look at distribution plots before conducting a test?

Answer 1

It is important to look at distribution plot before conducting a t-test because there are certain assumptions for a t-test to be valid. Among these assumptions, sampling of data must be done randomly from the population under consideration and the distribution of variable associated with this data follows a normal distribution is an important assumption for the validity of t-test and that's why to check the validity of this assumption it is important to look at distribution plot.

Note that, Student's t-distribution is basically a continuous probability distribution which arises from estimation of mean of a normally distributed population using small sample size and unknown population variance. Hence the assumption.

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