Answer:
b. $3,600,000.
Explanation:
The weighted average accumulated expenditure is given by the sum of each expenditure weighted by the distance between payment and the conclusion of the construction:
[tex]WAAE = \$3,000,000\frac{12-6}{12}+ \$6,300,000\frac{12-8}{12}+ \$6,000,000\frac{12-12}{12} \\WAAE = \$3,600,000[/tex]
Weighted average accumulated expenditures were $3,600,000.