Solve the proportion

x / 12 = 91 /84

Choose the best answer from the options below:
A 6
B 8
C 13
D 3

Cross multiplying the equation, we get x * 84 = 12 * 91. Simplifying the equation further, we get 84x = 1092. Dividing both sides of the equation by 84, we find that x = 13.

So, the answer is C) 13.

To solve the proportion x/12 = 91/84, we can cross-multiply:

12 * (91/84) = x

To simplify the left side of the equation, we multiply 12 by the fraction 91/84:

(12 * 91) / 84 = x

Now, we can multiply 12 by 91:

1092 / 84 = x

To simplify the left side of the equation, we divide 1092 by 84:

x = 13

Therefore, the value of x is 13. So, the correct answer is C.