Final answer:
The price of produce increased by approximately 57% while the price of processed food decreased by approximately 43%.
Step-by-step explanation:
The question asks about the changes in the price of produce and processed food since 1980. To answer this, we will look at the given information. From 1980 to 1990, real GDP grew by 39%, and prices increased by 51%. Assuming that the price of produce and processed food reflects the overall price trend, we can conclude that the price of produce increased by approximately 57% (51/(51+39)) and the price of processed food decreased by approximately 43% (39/(51+39)). Therefore, the correct answer would be option 3: 100% increase in the price of produce and 5% decrease in the price of processed food.