Advice from most financial advisers states to spend no more than $28\%$ of one's gross monthly income for one's mortgage payment, and to spend no more than $36\%$ of one's gross monthly income for one's total monthly debt. Suppose a family has a gross annual income of $$46,800.$

a$.$ What is the maximum amount the family should spend each month on a mortgage payment?

b$.$ What is the maximum amount the family should spend each month for total credit obligations?

c$.$ If the family's monthly mortgage payment is $60\%$ of the maximum they can afford, what is the maximum amount they should spend each month for all other debt?