How wouild statistics be used in a testing procedure?

Answer 1

Broad question! Focusing it would help us answer better.

Really basic stats would do things like tally and sum, average, find the median of the subjects you are testing.

Once you have those descriptive statistics, you can do things like compare outcomes between groups. Suppose you have two samples of people. One group has a mean life expectancy X. The other has mean life expectancy Y. To determine whether X and Y are significantly different from each other, you could do a Student t-test to determine whether the difference in values of X and Y are truly significant, or differ only by chance.

that's just one example. there are tons more!