Final answer:
The statement in the question is true. Factors such as disposable income and prices of competitors' products are demand determinants that are outside the direct control of a firm.
Step-by-step explanation:
The statement in the question is true. Other demand determinants, such as disposable income and prices of competitors' products, are factors that can shift the demand curve for goods and services. These determinants are outside the direct control of a firm, meaning the firm cannot directly manipulate them.
When disposable income increases, individuals have more money to spend on goods and services, leading to an increase in demand. On the other hand, if the prices of competitors' products decrease, consumers may switch their purchases to the competitors' products, resulting in a decrease in demand for the firm's products.