Final answer:
The mean change in visitors to National Parks per month, following a decrease of -12,080,530 people per year, is approximately -1,006,710 people when divided by 12 months.
Step-by-step explanation:
To calculate the mean change in visitors per month, you divide the total change in visitors by the number of months in a year. In this case, the change in visitors to National Parks is -12,080,530 people per year. There are 12 months in a year, so you would perform the following calculation:
Mean change per month = Total annual change ÷ Number of months
Mean change per month = -12,080,530 ÷ 12
Mean change per month = -1,006,710.83
Therefore, the average monthly change in visitors is approximately -1,006,710 people per month.