(ii) Of this gross amount, one-half shall be apportioned in accordance with the value of the taxpayer's property within the United States and within the foreign country, the portion attributable to sources within the United States being determined by multiplying such one-half by a fraction, the numerator of which consists of the value of the taxpayer's property within the United States and the denominator of which consists of the value of the taxpayer's property both within the United States and within the foreign country. The remaining one-half of such gross income shall be apportioned in accordance with the gross sales of the taxpayer within the United States and within the foreign country, the portion attributable to sources within the United States being determined by multiplying such one-half by a fraction the numerator of which consists of the taxpayer's gross sales for the taxable year or period within the United States, and the denominator of which consists of the taxpayer's gross sales for the taxable year or period both within the United States and within the foreign country. Deductions from gross income that are allocable and apportionable to gross income described in paragraph (i) of this Example 2 shall be apportioned between the United States and foreign source portions of such income, as determined under this paragraph (ii), on a pro rata basis, without regard to whether the deduction relates primarily or exclusively to the production of property or to the sale of property.