20. 21. 22. 23. What is the size of the substitution effect for good 1 when p1 decreases from $4 to $1? [Hint: for questions 20-23, you cannot use the mathematical approach developed in lecture and tutorial 5 to find the substitution and income effects. Applying here the graphical analysis of income and substitution effects should give you an idea of how to answer the question.] What is the size of the income effect for good 1 when ,0; decreases from $4 to $1? What is the size of the substitution effect for good 2 when p1 decreases from $4 to 51? What is the size of the income effect for good 2 when p1 decreases from $4 to $1