Finding the Fourth Proportional to 12,815.52, 17,685.20 and 7,226.56

Step by Step Solution

1. Step 1: Write the proportion equation
   12,815.52 : 17,685.20 = 7,226.56 : x
2. Step 2: Convert to fraction form
   12,815.52/17,685.20 = 7,226.56/x
3. Step 3: Cross multiply
   12,815.52x = 17,685.20 × 7,226.56
4. Step 4: Simplify right side
   12,815.52x = 127,803,158.91
5. Step 5: Solve for x
   x = 127,803,158.91/12,815.52
6. Step 6: Final answer
   x = 9,972.53