Finding the Fourth Proportional to 12,815.12, 17,682.16 and 7,781.96

Step by Step Solution

1. Step 1: Write the proportion equation
   12,815.12 : 17,682.16 = 7,781.96 : x
2. Step 2: Convert to fraction form
   12,815.12/17,682.16 = 7,781.96/x
3. Step 3: Cross multiply
   12,815.12x = 17,682.16 × 7,781.96
4. Step 4: Simplify right side
   12,815.12x = 137,601,861.83
5. Step 5: Solve for x
   x = 137,601,861.83/12,815.12
6. Step 6: Final answer
   x = 10,737.46