Finding the Fourth Proportional to 9,131.10, 12,812.70 and 9,131.10

Step by Step Solution

1. Step 1: Write the proportion equation
   9,131.10 : 12,812.70 = 9,131.10 : x
2. Step 2: Convert to fraction form
   9,131.10/12,812.70 = 9,131.10/x
3. Step 3: Cross multiply
   9,131.10x = 12,812.70 × 9,131.10
4. Step 4: Simplify right side
   9,131.10x = 116,994,044.97
5. Step 5: Solve for x
   x = 116,994,044.97/9,131.10
6. Step 6: Final answer
   x = 12,812.70