S Corporation has provided its contribution format income statement for January.

Sales $ $426,400$

Variable expenses $260,000$

Contribution margin $166,400$

Fixed expenses $120,900$

Net operating income $ $45,500$

If the company's sales volume increases by $7\%,$ its net operating income should increase by about:

Prompt $1$estimated percent increase in net operating income as the result of a $7\%$ increase in sales volume is closest to: