The value of nth term is calculated by the equation, an = (a1) x r^(n - 1) Using this equation to find for the common ratio, -8192 = 8 x r^(6 - 1) The value or r is -4. Using the same equation to find for the 12th term, a12 = 8 x (-4)^(12 - 1) a12 = -33554432