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 $$73,000.$

Self$-$employment income of $$73,000$ and wage income of $$32,000.$

Self$-$employment income of $$155,000.$

Self$-$employment income of $$357,000.$