Finding the Fourth Proportional to 9,123.10, 12,806.90 and 9,123.10

Step by Step Solution

1. Step 1: Write the proportion equation
   9,123.10 : 12,806.90 = 9,123.10 : x
2. Step 2: Convert to fraction form
   9,123.10/12,806.90 = 9,123.10/x
3. Step 3: Cross multiply
   9,123.10x = 12,806.90 × 9,123.10
4. Step 4: Simplify right side
   9,123.10x = 116,838,629.39
5. Step 5: Solve for x
   x = 116,838,629.39/9,123.10
6. Step 6: Final answer
   x = 12,806.90