Final answer:
The average change in temperature per day was 5 degrees, calculated by dividing the total temperature decrease of 30 degrees by the 6 days over which it occurred.
Step-by-step explanation:
To find the average change in temperature per day, you would divide the total change in temperature by the number of days. Since the temperature dropped a total of 30 degrees over 6 days, you do the following calculation:
Average change per day = Total change in temperature ÷ Number of days
Average change per day = 30° ÷ 6
Average change per day = 5°
Therefore, the average change in temperature per day was 5 degrees.