When you take a peek at t-distribution table or
the t-statistic calculator, you can see that one needs to know what
the “df” actually symbolizes. “df” is the “degrees of freedom” which
is just one less than the sample size.
Step-1: Subtract 1 from the sample size. This is the "df".
Step-2: Look for the "df" towards the left side of any
t-distribution table. Locate this column below the alpha level.