Final answer:
The total change in the number of bushels the farmer has for sale after 7 days is 112 bushels.
Step-by-step explanation:
The farmer starts with 180 bushels of apples and sells an average of 16 bushels each day for 7 days. To find the total change in the number of bushels he has for sale, we can multiply the average amount sold per day (16 bushels) by the number of days (7).
16 bushels/day x 7 days = 112 bushels
Therefore, the total change in the number of bushels the farmer has for sale after 7 days is 112 bushels.