To finance the development of a new product, a company borrowed $$46,400$ at $3\mathrm{.}94\%$ compounded quarterly. If the loan is to be repaid in equal quarterly payments $[$at the beginning$]$ of every quarter over seven years and the first payment is due three years after the date of the loan, what is the size of the quarterly payments?

Do not include the dollar sign, $$,$ in your answers.

Do not include the comma usually used to denote thousands.

$($a$.)$ How much is owed after the deferral period?

$($b$.)$ What is the size of the quarterly payments?

$($Hint: BGN must be up$)$