Let’s add two more columns to our table that contain the calculated and critical values of t and also the degrees of freedom.
|(standard error in the mean (SEM)||difference of means||SEDM||tcalc||tcrit (df=7)|
Our tcalc showed that the difference between tanks was about 5 times more than the random differences within tanks. And our tcrit showed that anything over 2.4 times would be statistically significant. So… finally, we can say definitively that Fish-2-Whale had a statistically significant effect on fish growth. Time to party!
Once more with gusto: if your tcalc is bigger than your tcrit, your results are statistically significant.