Finding the Fourth Proportional to 20,777.89, 28,671 and 13,118.26

Step by Step Solution

1. Step 1: Write the proportion equation
   20,777.89 : 28,671 = 13,118.26 : x
2. Step 2: Convert to fraction form
   20,777.89/28,671 = 13,118.26/x
3. Step 3: Cross multiply
   20,777.89x = 28,671 × 13,118.26
4. Step 4: Simplify right side
   20,777.89x = 376,113,632.46
5. Step 5: Solve for x
   x = 376,113,632.46/20,777.89
6. Step 6: Final answer
   x = 18,101.63