Finding the Fourth Proportional to 16,742.56, 25,211.72 and 12,390.56

Step by Step Solution

1. Step 1: Write the proportion equation
   16,742.56 : 25,211.72 = 12,390.56 : x
2. Step 2: Convert to fraction form
   16,742.56/25,211.72 = 12,390.56/x
3. Step 3: Cross multiply
   16,742.56x = 25,211.72 × 12,390.56
4. Step 4: Simplify right side
   16,742.56x = 312,387,329.36
5. Step 5: Solve for x
   x = 312,387,329.36/16,742.56
6. Step 6: Final answer
   x = 18,658.28