Finding the Fourth Proportional to 15,495.78, 21,385.98 and 9,208.15

Step by Step Solution

1. Step 1: Write the proportion equation
   15,495.78 : 21,385.98 = 9,208.15 : x
2. Step 2: Convert to fraction form
   15,495.78/21,385.98 = 9,208.15/x
3. Step 3: Cross multiply
   15,495.78x = 21,385.98 × 9,208.15
4. Step 4: Simplify right side
   15,495.78x = 196,925,311.74
5. Step 5: Solve for x
   x = 196,925,311.74/15,495.78
6. Step 6: Final answer
   x = 12,708.32