Ericka decided to compare her observation to the average annual trend, which shows the water rising 1.8 mm/year. Remember, she used 6.2 years as her time period. Explain how she would calculate the difference between how much water levels rose on average and how much the water level fell in the part of the river she observed. 1-2 sentences
To calculate the difference between the average annual rise and the observed decrease in water levels in the part of the river, Ericka would subtract the average annual rise of 1.8 mm/year from the observed decrease over 6.2 years.
