Songsu's small business can produce up to 1,000 units. He looks at his profit information from the past year and notes the following sales of $6,750. variable cost per unit of $5, fixed costs of $1,900, and operating income of $1,100. What was Songsu's sales volume last year? Sales volume What is the company's relevant range? Relevant range units to Determine the margin of safety in both units and sales dollars Margin of safety in units Margin of safety in dollars units units