Walmart Corporation has provided the following contribution format income statement. All questions concern situations that are within the relevant range.

	Sales (3,000 units)	$180,000
	Variable expenses	126,000
	Contribution margin	54,000
	Fixed expenses	52,200
	Net operating income	$1,800

Required:

a. If the selling price increases by $4 per unit and the sales volume decreases by 300 units, what would be the estimated net operating income?

b. If the variable cost per unit increases by $6, spending on advertising increases by $3,000, and unit sales increase by 1,800 units, what would be the estimated net operating income?