Step-by-step explanation:
Let's look at what we know. We know that...
P=2000
r=0.04 (Change 4% to a decimal)
t=7 (25 years minus 18 years equals 7)
n=1
Since we are compounding each year, we need to use this equation: 
Now just plug the numbers in: (Answer to #1:) 
This equals 2631.86
When we round, this equals to $2,632. (Answer to #2).
f(x) = 3 - 2sin(x)
0 = 3 - 2sin(x)
- 3 - 3
-3 = -2sin(x)
-2 -2
1¹/₂ = sin(x)
sin⁻¹(1¹/₂) = sin⁻¹[sin(x)]
sin⁻¹(1¹/₂) = x
So C/D=.34 And D=.11, now just plug D into the first equation.
C/.11=.34 Divide by .11
C=3.09090909
Now this rounded two decimal places is 3.09!
Hope this helps