Determine the maximum contribution that can be made to a Keogh plan in each of the following cases. In all instances, the individual is self-employed, and the self-employment tax reduction has already been taken. Required: a. Self-employment income of $54,000. b. Self-employment income of $54,000 and wage income of $30,000. c. Self-employment income of $125,000. d. Self-employment income of $290,000. Amount a. Maximum Keogh plan contribution b. Maximum Keogh plan contribution c. Maximum Keogh plan contribution d. Maximum Keogh plan contribution