Finding the Fourth Proportional to 12,185.57, 18,278.72 and 3,420.49

Step by Step Solution

1. Step 1: Write the proportion equation
   12,185.57 : 18,278.72 = 3,420.49 : x
2. Step 2: Convert to fraction form
   12,185.57/18,278.72 = 3,420.49/x
3. Step 3: Cross multiply
   12,185.57x = 18,278.72 × 3,420.49
4. Step 4: Simplify right side
   12,185.57x = 62,522,178.97
5. Step 5: Solve for x
   x = 62,522,178.97/12,185.57
6. Step 6: Final answer
   x = 5,130.84