Finding the Fourth Proportional to 12,428.93, 18,650.69 and 8,915.15

Step by Step Solution

1. Step 1: Write the proportion equation
   12,428.93 : 18,650.69 = 8,915.15 : x
2. Step 2: Convert to fraction form
   12,428.93/18,650.69 = 8,915.15/x
3. Step 3: Cross multiply
   12,428.93x = 18,650.69 × 8,915.15
4. Step 4: Simplify right side
   12,428.93x = 166,273,698.95
5. Step 5: Solve for x
   x = 166,273,698.95/12,428.93
6. Step 6: Final answer
   x = 13,377.96