Final answer:
When demand is high and supply is low, prices go up. When demand is low and supply is high, prices go down.
Step-by-step explanation:
The statement is true. When demand is high and supply is low, prices tend to go up. This is because when more consumers want to buy a certain product or service than what is available in the market, the sellers can charge higher prices due to the increased competition among buyers. On the other hand, when demand is low and supply is high, prices tend to go down. In this case, there is an excess supply of goods or services, and sellers need to lower the prices to attract buyers.