Finding the Fourth Proportional to 9,139.56, 12,612.48 and 4,947.72

Step by Step Solution

1. Step 1: Write the proportion equation
   9,139.56 : 12,612.48 = 4,947.72 : x
2. Step 2: Convert to fraction form
   9,139.56/12,612.48 = 4,947.72/x
3. Step 3: Cross multiply
   9,139.56x = 12,612.48 × 4,947.72
4. Step 4: Simplify right side
   9,139.56x = 62,403,019.55
5. Step 5: Solve for x
   x = 62,403,019.55/9,139.56
6. Step 6: Final answer
   x = 6,827.79