A company's master budget for October is to manufacture and sell 31,000 units, for a total sales revenue of $290,000, total variable costs of $166,000, and total fixed costs of $26,000. The company actually manufactured and sold 33,000 units, and generated $55,000 of operating income in October. The sales volume variance, in terms of operating income, for October was: (Do not round intermediate calculations.) Multiple Choice $6,630 favorable. $8,000 favorable. $20,370 favorable. $29,000 favorable.