The introduction of a new machine that makes the packaging of cake mixes more efficient is likely to increase the supply of cake mixes. When production becomes more efficient, producers can create more products at a lower cost, leading to an increase in supply.
As supply increases, if demand remains constant, the market price will typically decrease due to the higher availability of products.
Therefore, the correct statement describing how this improvement in technology will affect the market for cake mixes is:
Supply of cake mixes will increase, and market price will decrease.