Finding the Fourth Proportional to 12,804.55, 17,686.16 and 9,856.15

Step by Step Solution

1. Step 1: Write the proportion equation
   12,804.55 : 17,686.16 = 9,856.15 : x
2. Step 2: Convert to fraction form
   12,804.55/17,686.16 = 9,856.15/x
3. Step 3: Cross multiply
   12,804.55x = 17,686.16 × 9,856.15
4. Step 4: Simplify right side
   12,804.55x = 174,317,445.88
5. Step 5: Solve for x
   x = 174,317,445.88/12,804.55
6. Step 6: Final answer
   x = 13,613.71