Finding the Fourth Proportional to 12,165.36, 16,788.78 and 7,129.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,165.36 : 16,788.78 = 7,129.50 : x
2. Step 2: Convert to fraction form
   12,165.36/16,788.78 = 7,129.50/x
3. Step 3: Cross multiply
   12,165.36x = 16,788.78 × 7,129.50
4. Step 4: Simplify right side
   12,165.36x = 119,695,607.01
5. Step 5: Solve for x
   x = 119,695,607.01/12,165.36
6. Step 6: Final answer
   x = 9,839.05