Answer:
3
Step-by-step explanation:
This experiment has four groups. Each of these groups have six observations
Total number of observations = 4 x 6 = 24
Treatment degrees of freedom can be gotten by using this formula
Df1 = K - 1
= 4-1
= 3
Therefore for this question, the treatment degrees of freedom is given as 3 and the correct answer option is b.
