Finding the Fourth Proportional to 12,856.61, 19,275.59 and 8,686.19

Step by Step Solution

1. Step 1: Write the proportion equation
   12,856.61 : 19,275.59 = 8,686.19 : x
2. Step 2: Convert to fraction form
   12,856.61/19,275.59 = 8,686.19/x
3. Step 3: Cross multiply
   12,856.61x = 19,275.59 × 8,686.19
4. Step 4: Simplify right side
   12,856.61x = 167,431,340.72
5. Step 5: Solve for x
   x = 167,431,340.72/12,856.61
6. Step 6: Final answer
   x = 13,022.98