Finding the Fourth Proportional to 21,818.71, 30,109.76 and 12,745.85

Step by Step Solution

1. Step 1: Write the proportion equation
   21,818.71 : 30,109.76 = 12,745.85 : x
2. Step 2: Convert to fraction form
   21,818.71/30,109.76 = 12,745.85/x
3. Step 3: Cross multiply
   21,818.71x = 30,109.76 × 12,745.85
4. Step 4: Simplify right side
   21,818.71x = 383,774,420.77
5. Step 5: Solve for x
   x = 383,774,420.77/21,818.71
6. Step 6: Final answer
   x = 17,589.24