Finding the Fourth Proportional to 9,042.10, 12,688.10 and 9,042.10

Step by Step Solution

1. Step 1: Write the proportion equation
   9,042.10 : 12,688.10 = 9,042.10 : x
2. Step 2: Convert to fraction form
   9,042.10/12,688.10 = 9,042.10/x
3. Step 3: Cross multiply
   9,042.10x = 12,688.10 × 9,042.10
4. Step 4: Simplify right side
   9,042.10x = 114,727,069.01
5. Step 5: Solve for x
   x = 114,727,069.01/9,042.10
6. Step 6: Final answer
   x = 12,688.10