Finding the Fourth Proportional to 12,667.91, 18,991.61 and 5,277.92

Step by Step Solution

1. Step 1: Write the proportion equation
   12,667.91 : 18,991.61 = 5,277.92 : x
2. Step 2: Convert to fraction form
   12,667.91/18,991.61 = 5,277.92/x
3. Step 3: Cross multiply
   12,667.91x = 18,991.61 × 5,277.92
4. Step 4: Simplify right side
   12,667.91x = 100,236,198.25
5. Step 5: Solve for x
   x = 100,236,198.25/12,667.91
6. Step 6: Final answer
   x = 7,912.61