Finding the Fourth Proportional to 20,561.94, 28,388.88 and 12,608.55

Step by Step Solution

1. Step 1: Write the proportion equation
   20,561.94 : 28,388.88 = 12,608.55 : x
2. Step 2: Convert to fraction form
   20,561.94/28,388.88 = 12,608.55/x
3. Step 3: Cross multiply
   20,561.94x = 28,388.88 × 12,608.55
4. Step 4: Simplify right side
   20,561.94x = 357,942,612.92
5. Step 5: Solve for x
   x = 357,942,612.92/20,561.94
6. Step 6: Final answer
   x = 17,408.02