Finding the Fourth Proportional to 8,472.78, 12,709.98 and 3,279.06

Step by Step Solution

1. Step 1: Write the proportion equation
   8,472.78 : 12,709.98 = 3,279.06 : x
2. Step 2: Convert to fraction form
   8,472.78/12,709.98 = 3,279.06/x
3. Step 3: Cross multiply
   8,472.78x = 12,709.98 × 3,279.06
4. Step 4: Simplify right side
   8,472.78x = 41,676,787.02
5. Step 5: Solve for x
   x = 41,676,787.02/8,472.78
6. Step 6: Final answer
   x = 4,918.90