4. why doesn't a change in the price of eggs cause a change in the demand for eggs? what causes a shortage and how can it fairly quickly be resolved?

Eggs are a necessity and the price of eggs usually wouldn't change the demand of eggs because people need eggs enough to purchase them at any price.  It's also because a price change usually occurs as a result of a demand change, not the other way around (unless they lose a lot of money).  What causes a shortage is when there isn't enough of a product produced and it depends on the item as how quickly it can be fixed.  If it's a "made" product, then the turn around can be pretty quick.  It just comes down to the company making more.  But if it's a grown or produced product, like corn, it is up to the farming industry as to how fast it can be resolved. 

There's no picture attached but entrepreneur means a business person.