An alligator population in a nature preserve in the everglades decreases by 60 alligators over 5 years. what is the mean yearly change in the alligator population?

In order to calculate the mean, the average must be determined. In this scenario, the mean is determined by dividing 60 by 5. In this case, the mean yearly decrease in the alligator population is 12. (On a side note, this Website address is not responding.)