Please help me figure out how % of Revenue is calculated and how to calculate apportioned cost total and apportioned cost per lot.

Carla Vista Realty Company purchased a plot of ground for $1,890,000 and spent $3,900,000 in developing it for building lots. The lots were classified into Highland, Midland, and Lowland grades, to sell at $106,500,$79,875, and $53,250 each, respectively. Complete the table below to allocate the cost of the lots using a relative sales value method