Finding the Fourth Proportional to 12,856.09, 17,743.31 and 8,140.81

Step by Step Solution

1. Step 1: Write the proportion equation
   12,856.09 : 17,743.31 = 8,140.81 : x
2. Step 2: Convert to fraction form
   12,856.09/17,743.31 = 8,140.81/x
3. Step 3: Cross multiply
   12,856.09x = 17,743.31 × 8,140.81
4. Step 4: Simplify right side
   12,856.09x = 144,444,915.48
5. Step 5: Solve for x
   x = 144,444,915.48/12,856.09
6. Step 6: Final answer
   x = 11,235.52