b. Gross income. (Do not round intermediate calculations.) Foreign source income U.S. source income Falmouth Kettle Company, a U.S. corporation, sells its products in the United States and Europe. During the current year, selling, general, and administrative (SG&A) expenses included: Personnel department Training department President's salary Sales manager's salary Other general and administrative Total SG&A expenses $ 580 370 420 216 574 $2,160 Falmouth had $12,960 of gross sales to U.S. customers and $3,240 of gross sales to European customers. Gross income (sales minus cost of goods sold) from domestic sales was $3,240 and gross income from foreign sales was $1,080. Apportion Falmouth's SG&A expenses to foreign source and U.S. source income using the following methods: a. Gross sales. (Do not round intermediate calculations.) Foreign source income U.S. source income