Ericka observed the total variation in the water level over 6.2 years to be −13.64 mm. She compared this to the average annual trend, which shows the water level rising 1.8 mm/year. Remember, she used 6.2 years as her time period. What is the difference between how much average water levels rose and how much the water level fell in the part of the river she observed?

3.96mm/year

Step-by-step explanation:

Given that :

Given that:

Observed variation in water level over 6.2 years = - 13.64mm

Average annual trend shows rise in water level at 1.8 mm / year

difference between how much average water levels rose and how much the water level fell in the part of the river she observed?

Average Yearly observed variation :

Observed variation / number of years

-13.64mm / 6.2 years

= - 2.16 mm

Hence, observed yearly fall = - 2.16 mm

Yearly rise = 1.8mm / year

Difference :

( 1.8 mm/year) - (-2.16mm / year)

= (1.8 + 2.16) mm/year

= 3.96 mm/year

answer: i believe it is c

step-by-step explanation:

because 5+4=9 so it would be 3^9