Income on foreign investments is part of the Current account.
To determine whether it is a debit or a credit entry, remember that by convention,
Any inflow of domestic currency represents a credit and any outflow of domestic currency represents
*
a debit on the BOP account.
Any inflow of foreign currency represents a debit and any outflow of foreign currency represents a
*
credit on the BOP account.
Since the coupon income represents an inflow of domestic currency (from the foreign exchange markets, where the coupon payments in foreign currency were converted to domestic currency), it is a credit entry.

For example, the price of foreign currency is expressed in Euros in France and in CA$ in
Canada. Thus, in France, the CA$ might be quoted at Euro 0.5, whereas in Canada, the Euro would be quoted at CA$ 2.

Because the sample standard deviation is used (population standard deviation is unknown) a t-distribution is used. We find t(0.1, 15 - 1). Looking under column 0.10 and down to row 14 we get 1.345.
The rejection region is to left, so the critical value is -1.345.

The more perfectly a monopoly can price discriminate, the closer its output gets to the competitive output (P = MC) and the more efficient is the outcome.

6.33% x $3 million = $189,900