Finding the Fourth Proportional to 12,155.56, 16,759.32 and 9,915.16

Step by Step Solution

1. Step 1: Write the proportion equation
   12,155.56 : 16,759.32 = 9,915.16 : x
2. Step 2: Convert to fraction form
   12,155.56/16,759.32 = 9,915.16/x
3. Step 3: Cross multiply
   12,155.56x = 16,759.32 × 9,915.16
4. Step 4: Simplify right side
   12,155.56x = 166,171,339.29
5. Step 5: Solve for x
   x = 166,171,339.29/12,155.56
6. Step 6: Final answer
   x = 13,670.40