Finding the Fourth Proportional to 12,642.96, 17,427.42 and 8,657.18

Step by Step Solution

1. Step 1: Write the proportion equation
   12,642.96 : 17,427.42 = 8,657.18 : x
2. Step 2: Convert to fraction form
   12,642.96/17,427.42 = 8,657.18/x
3. Step 3: Cross multiply
   12,642.96x = 17,427.42 × 8,657.18
4. Step 4: Simplify right side
   12,642.96x = 150,872,311.88
5. Step 5: Solve for x
   x = 150,872,311.88/12,642.96
6. Step 6: Final answer
   x = 11,933.31