There are numerous information’s of immense importance already given in the question.
The number of teaspoons of baking soda required to make 4 dozens of cookies = 1
Then
The number of teaspoons of baking soda
required to make 1 dozens of cookies = (1/4) * 1
= 1/4
So 1/4 teaspoon of baking soda is required to make 1 dozen cookies. I hope I have helped you. I also hope that the procedure is clear enough for you to understand.