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:

Self$-$employment income of $$74,000.$

Self$-$employment income of $$74,000$ and wage income of $$33,000.$

Self$-$employment income of $$180,000.$

Self$-$employment income of $$358,000.$Amount

a$.$ Maximum Keogh plan contribution

b$.$ Maximum Keogh plan contribution

c$.$ Maximum Keogh plan contribution

d$.$ Maximum Keogh plan contribution