On March $1,$ Derby Corporation $($a U$.$S$.-$based company$)$ expects to order merchandise from a supplier in Norway in three months. On March $1,$ when the spot rate is $$0\mathrm{.}09$ per Norwegian krone, Derby enters into a forward contract to purchase $602,500$ Norwegian kroner at a three$-$month forward rate of $$0\mathrm{.}10.$ Forward points are excluded in assessing the forward contract's effectiveness as a hedge, and are amortized to net income on a straight$-$line basis. At the end of three months, when the spot rate is $$0\mathrm{.}098$ per Norwegian krone, Derby orders and receives the merchandise, paying $602,500$ kroner. The merchandise is sold within $30$ days.

Required:

a$-1.$ Prepare all journal entries for Derby Corporation related to this transaction and hedge.

a$-2.$ What amount should Derby Corporation report in the current year$$s net income as cost of goods sold?

b$.$ What amount should Derby Corporation report in the current year$$s net income as foreign exchange gain or loss?