Respuesta :

yes they move based on each other and are controlled by the seller not the consumer  
If a price of a product rises, then the amount of those products offered by suppliers will rise as well. The opposite works the same way: if the price decreases, then the amount of offered products decreases as well.
The logic is: if you see that you can sell something for more money, then you have a reason to produce more of that, because there is a high demand.