Finding the Fourth Proportional to 9,278.30, 12,789.50 and 7,031.18

Step by Step Solution

1. Step 1: Write the proportion equation
   9,278.30 : 12,789.50 = 7,031.18 : x
2. Step 2: Convert to fraction form
   9,278.30/12,789.50 = 7,031.18/x
3. Step 3: Cross multiply
   9,278.30x = 12,789.50 × 7,031.18
4. Step 4: Simplify right side
   9,278.30x = 89,925,276.61
5. Step 5: Solve for x
   x = 89,925,276.61/9,278.30
6. Step 6: Final answer
   x = 9,692.00