Final answer:
Linear break-even analysis and operating leverage are indeed only valid within a relevant range of production where certain conditions hold true, confirming the statement as true.
Step-by-step explanation:
The statement that linear break-even analysis and operating leverage are only valid within a relevant range of production is true. Break-even analysis presumes a linear relationship between sales and costs within a certain range, which reflects that fixed costs remain static up to a certain level of production or capacity. Beyond this level, the assumption of fixed costs may no longer hold as additional resources might be necessary, changing the cost structure. Therefore, the analysis is only accurate when applied within this range. Similarly, the concept of operating leverage assumes proportionate changes in profit due to changes in sales volume within a certain operational range. When production is increased beyond this range, economies of scale might diminish or additional costs might be incurred, altering the average cost of production and affecting the accuracy of the leverage calculations.