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

on friday there were 15 birds

the answer is 200

step-by-step explanation:

the way the question is worded, it seems to imply the $264 interest is simple interest, not compound interest.

the simple interest for 2 years is $264; the simple interest for 1 year is $132.

$132 interest on a $600 investment means an interest rate of (132/600)*100 = 22%.

the value of $200 at 22% interest compounded annually for three years is

200%281.22%29%5e3

the amount of interest is that value, minus the original $200.