Finding the Fourth Proportional to 9,786.78, 13,487.10 and 9,606.83

Step by Step Solution

1. Step 1: Write the proportion equation
   9,786.78 : 13,487.10 = 9,606.83 : x
2. Step 2: Convert to fraction form
   9,786.78/13,487.10 = 9,606.83/x
3. Step 3: Cross multiply
   9,786.78x = 13,487.10 × 9,606.83
4. Step 4: Simplify right side
   9,786.78x = 129,568,209.46
5. Step 5: Solve for x
   x = 129,568,209.46/9,786.78
6. Step 6: Final answer
   x = 13,239.11