Finding the Fourth Proportional to 12,859.56, 17,748.72 and 8,140.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,859.56 : 17,748.72 = 8,140.50 : x
2. Step 2: Convert to fraction form
   12,859.56/17,748.72 = 8,140.50/x
3. Step 3: Cross multiply
   12,859.56x = 17,748.72 × 8,140.50
4. Step 4: Simplify right side
   12,859.56x = 144,483,455.16
5. Step 5: Solve for x
   x = 144,483,455.16/12,859.56
6. Step 6: Final answer
   x = 11,235.49