suppose the firm wishes to increase its sales of Good B by 12%. Calculate by how much (in %) the firm should change the price of Good B to achieve this objective?

Profit maximizing price of Good A = $6000

MC at profit maximizing level of output of Good A = $1200

MC at profit maximizing level of output of Good B = $400

Total revenue of Good A = $80000

Total revenue of Good B = $68000

Rothschild index of Good B = 0.6

Price elasticity of the market demand for Good B = -1.2