The answer would be 24pi inches.
You can find this by using the formula for a circumference and plugging in the value of the radius.
C = 2pi*r
C = 2pi * 12
C = 24pi
For this problem, I'd use cross-multiplication.
9/12 = x/8.
When cross multiplying, multiply 12*x and 9*8. This leads to a new equation:
12x = 72.
Then you solve as an algebra problem.
*Divide 12 on both sides*
x = 6.
You subtract 38.75 from 46.5, which is 7.75. 7.75/46.5=about .16666, or 16.7 percent.
Year 1: 500 + 0.25*500 = 500 [1 + 0.25]
Year 2: 500*[ 1 + 0.25] * [1 + 0.25] = 500 [1 + 0.25]^2
Year x: 500 [1 + 0.25]^x
Option d: A(x) = 500[1 + .25]^x, where .25 is the interest rate
