Finding the Fourth Proportional to 12,810.76, 19,189.17 and 10,856.09

Step by Step Solution

1. Step 1: Write the proportion equation
   12,810.76 : 19,189.17 = 10,856.09 : x
2. Step 2: Convert to fraction form
   12,810.76/19,189.17 = 10,856.09/x
3. Step 3: Cross multiply
   12,810.76x = 19,189.17 × 10,856.09
4. Step 4: Simplify right side
   12,810.76x = 208,319,404.52
5. Step 5: Solve for x
   x = 208,319,404.52/12,810.76
6. Step 6: Final answer
   x = 16,261.29