Final answer:
To find the probability that all four adults are very confident in the nutritional information on restaurant menus, we need to know the proportion of adults who are very confident. The probability that all four adults are very confident is p^4.
Step-by-step explanation:
To find the probability that all four adults are very confident in the nutritional information on restaurant menus, we need to know the proportion of adults who are very confident. Let's assume this proportion is p. The probability that a randomly selected adult is very confident is p. Since the adults are selected independently, the probability that all four adults are very confident is p * p * p * p, or p4.