A loan of $$21,200\mathrm{.}00$ at $3\mathrm{.}50\%$ compounded semi$-$annually is to be repaid with payments at the end of every $6$ months. The loan was settled in $4$ years.

a$.$ Calculate the size of the periodic payment.

$$2,566\mathrm{.}43$

$$3,084\mathrm{.}10$

$$2,862\mathrm{.}91$

$$3,244\mathrm{.}25$

b$.$ Calculate the total interest paid.

$$1,703\mathrm{.}28$

$$22,903\mathrm{.}28$

$-$$$1,159\mathrm{.}63$

$$4,566\mathrm{.}19$