Your client wants to purchase a new home for $ $300,000$ and finance $ $250,000$ with a $4\mathrm{.}25\%,30-$year fixed mortgage. a$.$ What is the monthly payment for principal and interest for this mortgage? b$.$ How much interest would be paid in the first $12$ payments? $.$ What would the loan balance be after $10$ years, assuming all payments were paid on time?