Finding the Fourth Proportional to 9,139.05, 12,611.88 and 4,947.30

Step by Step Solution

1. Step 1: Write the proportion equation
   9,139.05 : 12,611.88 = 4,947.30 : x
2. Step 2: Convert to fraction form
   9,139.05/12,611.88 = 4,947.30/x
3. Step 3: Cross multiply
   9,139.05x = 12,611.88 × 4,947.30
4. Step 4: Simplify right side
   9,139.05x = 62,394,753.92
5. Step 5: Solve for x
   x = 62,394,753.92/9,139.05
6. Step 6: Final answer
   x = 6,827.27