Finding the Fourth Proportional to 9,139.80, 12,348.45 and 9,139.80

Step by Step Solution

1. Step 1: Write the proportion equation
   9,139.80 : 12,348.45 = 9,139.80 : x
2. Step 2: Convert to fraction form
   9,139.80/12,348.45 = 9,139.80/x
3. Step 3: Cross multiply
   9,139.80x = 12,348.45 × 9,139.80
4. Step 4: Simplify right side
   9,139.80x = 112,862,363.31
5. Step 5: Solve for x
   x = 112,862,363.31/9,139.80
6. Step 6: Final answer
   x = 12,348.45