Jackie Chiles recently bought a new condominium and took out a $30-$year fixed mortgage in the amount of $$375,000$ with a nominal interest rate of $7\mathrm{.}5\%.$

$1.$ How much are Jackie$$s monthly payments?

$2.$ What proportion $(\%)$ of Jackie$$s mortgage payments made during the first $5$ years will be applied to interest?

$3.$ What will be the outstanding balance on Jackie$$s mortgage after $7$ years of making consistent, regular mortgage payments?